User-configurable closed-loop notifications and infusion systems incorporating same

ABSTRACT

A system includes one or more processors, and one or more processor-readable storage media storing instructions which, when executed by the one or more processors, cause performance of: switching operation of an infusion device from a first mode of fluid delivery to a second mode of fluid delivery, the first mode being different from the second mode, receiving user input after the infusion device is operating in the second mode, the user input being indicative of whether the infusion device should remain operating in the second mode or transition from the second mode to a different mode, and operating the infusion device in a manner that is influenced by the user input.

This application is a continuation of U.S. patent application Ser. No.15/828,340, filed Nov. 30, 2017, which is a divisional of U.S. patentapplication Ser. No. 14/174,487, filed Feb. 6, 2014, and now U.S. Pat.No. 9,861,748, the entire content of each of which is incorporatedherein by reference.

TECHNICAL FIELD

Embodiments of the subject matter described herein relate generally tomedical devices, and more particularly, embodiments of the subjectmatter relate to generating user notifications while providingclosed-loop control of a fluid infusion device.

BACKGROUND

Infusion pump devices and systems are relatively well known in themedical arts, for use in delivering or dispensing an agent, such asinsulin or another prescribed medication, to a patient. A typicalinfusion pump includes a pump drive system which typically includes asmall motor and drive train components that convert rotational motormotion to a translational displacement of a plunger (or stopper) in areservoir that delivers medication from the reservoir to the body of auser via a fluid path created between the reservoir and the body of auser. Use of infusion pump therapy has been increasing, especially fordelivering insulin for diabetics.

Continuous insulin infusion provides greater control of a diabetic'scondition, and hence, control schemes are being developed that allowinsulin infusion pumps to monitor and regulate a user's blood glucoselevel in a substantially continuous and autonomous manner, for example,overnight while the user is sleeping. It is desirable to providecontinuous insulin infusion control schemes that are capable of safelyregulating a user's blood glucose level without interfering with theuser's daily activities (e.g., without waking a user overnight). Thatsaid, some users prefer a more hands-on approach to managing their bloodglucose level.

BRIEF SUMMARY

In one example, a system includes one or more processors, and one ormore processor-readable storage media storing instructions which, whenexecuted by the one or more processors, cause performance of: switchingoperation of an infusion device from a first mode of fluid delivery to asecond mode of fluid delivery, the first mode being different from thesecond mode, receiving user input after the infusion device is operatingin the second mode, the user input being indicative of whether theinfusion device should remain operating in the second mode or transitionfrom the second mode to a different mode, and operating the infusiondevice in a manner that is influenced by the user input.

In one example, a processor-implemented method includes switchingoperation of an infusion device from a first mode of fluid delivery to asecond mode of fluid delivery, the first mode being different from thesecond mode, receiving user input after the infusion device is operatingin the second mode, the user input being indicative of whether theinfusion device should remain operating in the second mode or transitionfrom the second mode to a different mode, and operating the infusiondevice in a manner that is influenced by the user input.

In one example, one or more non-transitory processor-readable storagemedia storing instructions which, when executed by one or moreprocessors, cause performance of: switching operation of an infusiondevice from a first mode of fluid delivery to a second mode of fluiddelivery, the first mode being different from the second mode, receivinguser input after the infusion device is operating in the second mode,the user input being indicative of whether the infusion device shouldremain operating in the second mode or transition from the second modeto a different mode, and operating the infusion device in a manner thatis influenced by the user input.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the subject matter may be derived byreferring to the detailed description and claims when considered inconjunction with the following figures, wherein like reference numbersrefer to similar elements throughout the figures, which may beillustrated for simplicity and clarity and are not necessarily drawn toscale.

FIG. 1 depicts an exemplary embodiment of an infusion system;

FIG. 2 is a perspective view of an exemplary embodiment of a fluidinfusion device suitable for use in the infusion system of FIG. 1;

FIG. 3 is a perspective view that depicts the internal structure of thedurable housing of the fluid infusion device shown in FIG. 2;

FIG. 4 is a block diagram of a closed-loop infusion system suitable foruse with the infusion system of FIG. 1;

FIG. 5 is a block diagram that illustrates processing modules andalgorithms of an exemplary embodiment of a control system suitable foruse with the closed-loop infusion system of FIG. 4;

FIG. 6 is a flow diagram of an exemplary control process suitable foruse with the control system of FIG. 5;

FIG. 7 is a block diagram of an exemplary infusion system suitable foruse with the closed-loop infusion system of FIGS. 4-6;

FIG. 8 is a block diagram of an exemplary pump control system suitablefor use in the infusion system of FIG. 7;

FIG. 9 is a flow diagram of an exemplary alerting process suitable foruse with an infusion system; and

FIG. 10 is a flow diagram of an exemplary adaptive response processsuitable for use in conjunction with the alerting process of FIG. 9.

DETAILED DESCRIPTION

The following detailed description is merely illustrative in nature andis not intended to limit the embodiments of the subject matter or theapplication and uses of such embodiments. As used herein, the word“exemplary” means “serving as an example, instance, or illustration.”Any implementation described herein as exemplary is not necessarily tobe construed as preferred or advantageous over other implementations.Furthermore, there is no intention to be bound by any expressed orimplied theory presented in the preceding technical field, background,brief summary or the following detailed description.

While the subject matter described herein can be implemented in anyelectronic device that includes a motor, exemplary embodiments describedbelow are implemented in the form of medical devices, such as portableelectronic medical devices. Although many different applications arepossible, the following description focuses on a fluid infusion device(or infusion pump) as part of an infusion system deployment. For thesake of brevity, conventional techniques related to infusion systemoperation, insulin pump and/or infusion set operation, and otherfunctional aspects of the systems (and the individual operatingcomponents of the systems) may not be described in detail here. Examplesof infusion pumps may be of the type described in, but not limited to,U.S. Pat. Nos. 4,562,751; 4,685,903; 5,080,653; 5,505,709; 5,097,122;6,485,465; 6,554,798; 6,558,320; 6,558,351; 6,641,533; 6,659,980;6,752,787; 6,817,990; 6,932,584; and 7,621,893; each of which are hereinincorporated by reference.

Embodiments of the subject matter described herein generally relate tofluid infusion devices including a motor that is operable to displace aplunger (or stopper) of a reservoir provided within the fluid infusiondevice and deliver a dosage of fluid, such as insulin, to the body of auser. As described in greater detail below, during a closed-loop controlmode, delivery commands (or dosage commands) that govern operation ofthe motor are determined based on a difference between a measured valuefor a condition in the body of the user and a target value to regulatethe condition in the body of the user to the target value. Whileoperating the infusion device to provide closed-loop control, a numberof different conditions may be detected that are indicative of potentialanomalous conditions that may impact the operations of the closed-loopcontrol. For example, limits or other thresholds imposed to preventinadvertent overdelivery or underdelivery, ensure sensing arrangementsare functioning properly within their calibration range, and the like.These conditions detected while operating the infusion device in theclosed-loop mode may be used to initiate or otherwise trigger analternative control of the infusion device instead of the closed-loopcontrol (e.g., an open-loop mode, or the like). Additionally, theconditions detected while operating the infusion device in theclosed-loop mode may be used to initiate or otherwise trigger thegeneration of user notifications or alerts, and accordingly, suchconditions that may be detected during the closed-loop mode arealternatively referred to herein as alert conditions.

In exemplary embodiments, the user notifications that are provided inresponse to detection of a particular alert condition during theclosed-loop mode are configurable for the individual user associatedwith the infusion device. In other words, each user may define analerting scheme that is unique and tailored to his or her individualpreferences, and thus, the user notifications are generated in auser-specific manner based on that user's alert configurationinformation. In this regard, whether or not a user notification isgenerated for a particular alert condition may be chosen by the user,and furthermore, the type and/or number of user notifications generatedfor a particular alert condition may also be chosen by the user.Additionally, the user may configure other parameters associated withthe user notifications, such as, for example, whether a usernotification should be repeated and/or how frequently a usernotification should be repeated if the user has not responded to thenotification, what user-specific thresholds should be utilized todetermine the type and/or number of user notifications to be generated,the content of the user notifications, one or more destination addressesfor a user notification (e.g., for a remote notification via textmessage, e-mail, or the like), and the like.

As described in greater detail below in the context of FIGS. 9-10, thealert configuration information for an individual user is received andstored or otherwise maintained for reference during the closed-loopmode. During the closed-loop mode, when an alert condition isidentified, the user's alert configuration information is consulted todetermine whether any user notifications should be generated, and if so,the type and/or number of user notifications to be generated.Thereafter, the appropriate user notifications are automaticallygenerated in accordance with the user-specific alert configurationinformation. After a user notification is generated, the user may submitor otherwise provide a response to the user notification, whereby thesubsequent operation of the infusion device is influenced by theresponse to the user notification.

For example, the user may manipulate a blood glucose meter (e.g., afinger stick device or the like) to submit an updated (or new) bloodglucose measurement from the body of the user for use as an updated (ornew) reference value for the closed-loop control. Based on the updatedblood glucose reference measurement value, the functionality and/oroperation of the closed-loop control may be verified or otherwiseconfirmed, for example, by comparing the updated blood glucose referencemeasurement value to recent sensor glucose measurement values determinedbased on the measurement data from another glucose sensing arrangement(e.g., an interstitial glucose sensing arrangement). When the accuracyof the closed-loop control and/or the glucose sensing arrangement isverified, the closed-loop mode is reinitialized, restarted, or otherwisereinitiated based at least in part on the updated blood glucosereference measurement value, such that closed-loop operation of theinfusion device is provided or otherwise maintained after the alertcondition was detected. If the updated blood glucose referencemeasurement value indicates that the glucose sensing arrangement is outof calibration by an amount that can be corrected by recalibration, oneor more updated (or new) sensor calibration factors are determined usingthe updated blood glucose reference measurement value beforereinitializing the closed-loop mode using the updated blood glucosereference measurement value and the updated sensor calibration factor(s)in lieu of the initial blood glucose reference measurement value and theinitial sensor calibration factor(s) that were implemented prior toidentifying the alert condition. In this manner, the closed-loop controlis adaptive or otherwise responsive to a user's response to a previouslygenerated user notification, such that closed-loop operation of theinfusion device is provided or otherwise maintained after the alertcondition was detected using different reference values and/orcalibration factors when generating delivery commands.

Alternatively, if the updated blood glucose reference measurement valueindicates an anomalous condition of the glucose sensing arrangementand/or the closed-loop control, another user notification may begenerated that apprises the user of the anomalous condition and analternative control of the infusion device is implemented. In a similarmanner as described above, the anomalous condition user notification mayalso be generated in a user-specific manner in accordance with theindividual user's alert configuration information. Similarly, if theupdated blood glucose reference measurement value indicates a low bloodglucose condition of the user, yet another user notification may begenerated in accordance with the individual user's alert configurationinformation to apprise the user of the low blood glucose condition.

Turning now to FIG. 1, one exemplary embodiment of an infusion system100 includes, without limitation, a fluid infusion device (or infusionpump) 102, a sensing arrangement 104, a command control device (CCD)106, and a computing device (or computer) 108. The components of aninfusion system 100 may be realized using different platforms, designs,and configurations, and the embodiment shown in FIG. 1 is not exhaustiveor limiting. In practice, the infusion device 102 and the sensingarrangement 104 are secured at desired locations on the body of a user(or patient), as illustrated in FIG. 1. In this regard, the locations atwhich the infusion device 102 and the sensing arrangement 104 aresecured to the body of the user in FIG. 1 are provided only as arepresentative, non-limiting, example. The elements of the infusionsystem 100 may be similar to those described in U.S. patent applicationSer. No. 13/049,803, the subject matter of which is hereby incorporatedby reference in its entirety.

In the illustrated embodiment of FIG. 1, the infusion device 102 isdesigned as a portable medical device suitable for infusing a fluid, aliquid, a gel, or other agent into the body of a user. In exemplaryembodiments, the infused fluid is insulin, although many other fluidsmay be administered through infusion such as, but not limited to, HIVdrugs, drugs to treat pulmonary hypertension, iron chelation drugs, painmedications, anti-cancer treatments, medications, vitamins, hormones, orthe like. In some embodiments, the fluid may include a nutritionalsupplement, a dye, a tracing medium, a saline medium, a hydrationmedium, or the like.

The sensing arrangement 104 generally represents the components of theinfusion system 100 configured to sense, detect, measure or otherwisequantify a condition of the user, and may include a sensor, a monitor,or the like, for providing data indicative of the condition that issensed, detected, measured or otherwise monitored by the sensingarrangement. In this regard, the sensing arrangement 104 may includeelectronics and enzymes reactive to a biological condition, such as ablood glucose level, or the like, of the user, and provide dataindicative of the blood glucose level to the infusion device 102, theCCD 106 and/or the computer 108. For example, the infusion device 102,the CCD 106 and/or the computer 108 may include a display for presentinginformation or data to the user based on the sensor data received fromthe sensing arrangement 104, such as, for example, a current glucoselevel of the user, a graph or chart of the user's glucose level versustime, device status indicators, alert messages, or the like. In otherembodiments, the infusion device 102, the CCD 106 and/or the computer108 may include electronics and software that are configured to analyzesensor data and operate the infusion device 102 to deliver fluid to thebody of the user based on the sensor data and/or preprogrammed deliveryroutines. Thus, in exemplary embodiments, one or more of the infusiondevice 102, the sensing arrangement 104, the CCD 106, and/or thecomputer 108 includes a transmitter, a receiver, and/or othertransceiver electronics that allow for communication with othercomponents of the infusion system 100, so that the sensing arrangement104 may transmit sensor data or monitor data to one or more of theinfusion device 102, the CCD 106 and/or the computer 108.

Still referring to FIG. 1, in various embodiments, the sensingarrangement 104 may be secured to the body of the user or embedded inthe body of the user at a location that is remote from the location atwhich the infusion device 102 is secured to the body of the user. Invarious other embodiments, the sensing arrangement 104 may beincorporated within the infusion device 102. In other embodiments, thesensing arrangement 104 may be separate and apart from the infusiondevice 102, and may be, for example, part of the CCD 106. In suchembodiments, the sensing arrangement 104 may be configured to receive abiological sample, analyte, or the like, to measure a condition of theuser.

As described above, in some embodiments, the CCD 106 and/or the computer108 may include electronics and other components configured to performprocessing, delivery routine storage, and to control the infusion device102 in a manner that is influenced by sensor data measured by and/orreceived from the sensing arrangement 104. By including controlfunctions in the CCD 106 and/or the computer 108, the infusion device102 may be made with more simplified electronics. However, in otherembodiments, the infusion device 102 may include all control functions,and may operate without the CCD 106 and/or the computer 108. In variousembodiments, the CCD 106 may be a portable electronic device. Inaddition, in various embodiments, the infusion device 102 and/or thesensing arrangement 104 may be configured to transmit data to the CCD106 and/or the computer 108 for display or processing of the data by theCCD 106 and/or the computer 108.

In some embodiments, the CCD 106 and/or the computer 108 may provideinformation to the user that facilitates the user's subsequent use ofthe infusion device 102. For example, the CCD 106 may provideinformation to the user to allow the user to determine the rate or doseof medication to be administered into the user's body. In otherembodiments, the CCD 106 may provide information to the infusion device102 to autonomously control the rate or dose of medication administeredinto the body of the user. In some embodiments, the sensing arrangement104 may be integrated into the CCD 106. Such embodiments may allow theuser to monitor a condition by providing, for example, a sample of hisor her blood to the sensing arrangement 104 to assess his or hercondition. In some embodiments, the sensing arrangement 104 and the CCD106 may be used for determining glucose levels in the blood and/or bodyfluids of the user without the use of, or necessity of, a wire or cableconnection between the infusion device 102 and the sensing arrangement104 and/or the CCD 106.

In some embodiments, the sensing arrangement 104 and/or the infusiondevice 102 are cooperatively configured to utilize a closed-loop systemfor delivering fluid to the user. Examples of sensing devices and/orinfusion pumps utilizing closed-loop systems may be found at, but arenot limited to, the following U.S. Pat. Nos. 6,088,608, 6,119,028,6,589,229, 6,740,072, 6,827,702, 7,323,142, and 7,402,153 or U.S. patentapplication Ser. No. 13/966,120, all of which are incorporated herein byreference in their entirety. In such embodiments, the sensingarrangement 104 is configured to sense or measure a condition of theuser, such as, blood glucose level or the like. The infusion device 102is configured to deliver fluid in response to the condition sensed bythe sensing arrangement 104. In turn, the sensing arrangement 104continues to sense or otherwise quantify a current condition of theuser, thereby allowing the infusion device 102 to deliver fluidcontinuously in response to the condition currently (or most recently)sensed by the sensing arrangement 104 indefinitely. In some embodiments,the sensing arrangement 104 and/or the infusion device 102 may beconfigured to utilize the closed-loop system only for a portion of theday, such as, for example, only when the user is asleep (e.g.,overnight). In this regard, in some embodiments, the closed-loop controlmay be implemented for a limited duration of time (e.g., an 8 hour timelimit) before being disabled or otherwise unavailable for a thresholdamount of time before the closed-loop control can be reinitiated.

FIGS. 2-3 depict an exemplary embodiment of a fluid infusion device 200suitable for use as the infusion device 102 in the infusion system 100of FIG. 1. FIGS. 2-3 depict perspective views of the fluid infusiondevice 200, which includes a durable housing 202 and a base plate 204.While FIG. 2 depicts the durable housing 202 and the base plate 204 asbeing coupled together, in practice, the durable housing 202 and/or thebase plate 204 may include features, structures, or elements tofacilitate removable coupling (e.g., pawls, latches, rails, slots,keyways, buttons, or the like) and accommodate a removable/replaceablefluid reservoir 206. As illustrated in FIG. 3, in exemplary embodiments,the fluid reservoir 206 mates with, and is received by, the durablehousing 202. In alternate embodiments, the fluid reservoir 206 mateswith, and is received by, the base plate 204.

In exemplary embodiments, the base plate 204 is temporarily adhered tothe skin of the user, as illustrated in FIG. 1 using, for example, anadhesive layer of material. After the base plate 204 is affixed to theskin of the user, a suitably configured insertion device or apparatusmay be used to insert a fluid delivery needle or cannula 208 into thebody of the user. The cannula 208 functions as one part of the fluiddelivery path associated with the fluid infusion device 200. The durablehousing 202 receives the fluid reservoir 206 and retains the fluidreservoir 206 in a substantially fixed position and orientation withrespect to the durable housing 202 and the base place 204 while thedurable housing 202 and the base plate 204 are coupled. The durablehousing 202 is configured to secure to the base plate 204 in a specifiedorientation to engage the fluid reservoir 206 with a reservoir portreceptacle formed in the durable housing 202. In particular embodiments,the fluid infusion device 200 includes certain features to orient,align, and position the durable housing 202 relative to the base plate204 such that when the two components are coupled together, the fluidreservoir 206 is urged into the reservoir port receptacle to engage asealing assembly and establish a fluid seal.

In exemplary embodiments, the fluid reservoir 206 includes a fluiddelivery port 210 that cooperates with the reservoir port receptacle toestablish a fluid delivery path. In this regard, the fluid delivery port210 has an interior 211 defined therein that is shaped, sized, andotherwise configured to receive a sealing element when the fluidreservoir 206 is engaged with the reservoir port receptacle on baseplate 204. The sealing element forms part of a sealing assembly for thefluid infusion device 200 and preferably includes one or more sealingelements and/or fluid delivery needles configured to establish fluidcommunication from the interior of the reservoir 206 to the cannula 208via the fluid delivery port 210 and a mounting cap 212, and therebyestablish a fluid delivery path from the reservoir 206 to the user viathe cannula 208. In the illustrated embodiment, the fluid reservoir 206includes a second fluid port for receiving fluid. For example, thesecond fluid port 213 may include a pierceable septum, a vented opening,or the like to accommodate filling (or refilling) of the fluid reservoir206 by the patient, a doctor, a caregiver, or the like.

As illustrated in FIG. 3, the reservoir 206 includes a barrel 220 forcontaining fluid and a plunger 222 (or stopper) positioned to push fluidfrom inside the barrel 220 of the reservoir 206 along the fluid paththrough the cannula 208 to the user. A shaft 224 is mechanically coupledto or otherwise engages the plunger 222, and the shaft 224 has exposedteeth 225 that are configured to mechanically couple or otherwise engagethe shaft 224 with a gear 238 of a drive system 230 contained in thedurable housing 202. In this regard, the shaft 224 functions as a rackgear as part of a rack and pinion gear configuration. Although thesubject matter may be described herein in the context of the shaft 224being integral with or otherwise part of the plunger 222, in practice,the shaft 224 and the plunger 222 may be provided separately.

Various aspects of the motor drive system 230 may be similar to thosedescribed in U.S. patent application Ser. No. 13/049,803. The drivesystem 230 includes a motor 232 having a rotor that is mechanicallycoupled to a gear assembly 236 that translates rotation of the rotor totranslational displacement the plunger 222 in the direction 250 of thefluid delivery port 210 to deliver fluid from the reservoir 206 to auser. Accordingly, the direction 250 may alternatively be referred toherein as the fluid delivery direction 250.

In exemplary embodiments, the motor 232 is realized as a DC motor, suchas a stepper motor or brushless DC motor capable of preciselycontrolling the amount of displacement of the plunger 222 duringoperation of the infusion device 200. In exemplary embodiments, therotor of the motor 232 is mechanically coupled to a rotary shaft, which,in turn, is mechanically coupled to a first gear of the gear assembly236. For example, the first gear may be coaxial and/or concentric to anddisposed about the rotary shaft, where the first gear is affixed to orotherwise integrated with the rotary shaft such that the first gear andthe rotary shaft rotate in unison. The gear assembly 236 also includes apinion gear 238 having exposed teeth 239 that are configured to matewith or otherwise engage the exposed teeth 225 on the shaft 224 when thereservoir 206 is seated in the durable housing 202, such that rotationor displacement of the pinion gear 238 in rotational delivery direction350 produces a corresponding translational displacement of the shaft 224and/or plunger 222 in the fluid delivery direction 250 to deliver fluidto the user.

During operation of the fluid infusion device 200, when the motor 232 isoperated to rotate the rotor, the rotary shaft rotates in unison withthe rotor to cause a corresponding rotation of the first gear, which, inturn, actuates the gears of the gear assembly 236 to produce acorresponding rotation or displacement of the pinion gear 238, which, inturn, displaces the shaft 224. In this manner, the rotary shafttranslates rotation (or displacement) of the rotor into a correspondingrotation (or displacement) of the gear assembly 236 such that the teeth239 of the pinion gear 238 apply force to the teeth 225 of the shaft 224of the plunger 222 in the fluid delivery direction 250 to therebydisplace the plunger 222 in the fluid delivery direction 250 anddispense, expel, or otherwise deliver fluid from the barrel 220 of thereservoir 206 to the user via the fluid delivery path provided by thecannula 208.

As described in greater detail below in the context of FIG. 7, in one ormore exemplary embodiments, a motor position sensor (or rotor positionsensor) is configured to measure, sense, or otherwise detect rotation(or displacement) of the rotary shaft and/or the rotor of the motor 232.The motor position sensor may be utilized to provide closed-loop controlof the motor 232, such as, for example, as described in U.S. Pat. No.8,603,026, the subject matter of which is hereby incorporated byreference in its entirety. In exemplary embodiments, the rotary shaftincludes, is coupled to, or is otherwise associated with a detectablefeature that is measurable or otherwise detectable by the motor positionsensor. In this regard, the detectable feature may rotate in unison withthe rotary shaft. In one or more embodiments, the motor position sensoris realized as an incremental position sensor configured to measure,sense, or otherwise detect incremental rotations of the rotary shaftand/or the rotor of the motor 232. For example, in accordance with oneor more embodiments, the motor position sensor is realized as a rotaryencoder.

FIG. 4 depicts an exemplary embodiment of a closed-loop infusion system400 suitable for use with or implementation by the infusion system 100for regulating the rate of fluid infusion into a body of a user (e.g.,by infusion device 102) based on feedback from an analyte concentrationmeasurement taken from the body (e.g., via sensing arrangement 104). Inexemplary embodiments, the infusion system 400 regulates the rate ofinsulin infusion into the body of a user based on a glucoseconcentration measurement taken from the body. In preferred embodiments,the infusion system 400 is designed to model a pancreatic beta cell(β-cell). In other words, the system controls the infusion device 102 torelease insulin into a body of a user in a similar concentration profileas would be created by fully functioning human β-cells when respondingto changes in blood glucose concentrations in the body. Thus, theinfusion system 400 simulates the body's natural insulin response toblood glucose levels and not only makes efficient use of insulin, butalso accounts for other bodily functions as well since insulin has bothmetabolic and mitogenic effects. However, the algorithms must model theβ-cells closely, since algorithms that are designed to minimize glucoseexcursions in the body, without regard for how much insulin isdelivered, may cause excessive weight gain, hypertension, andatherosclerosis. Thus, in some embodiments, the infusion system 400 isintended to emulate the in vivo insulin secretion pattern and to adjustthis pattern consistent with the in vivo β-cell adaptation experiencedby normal healthy individuals with normal glucose tolerance (NGT).

The illustrated closed-loop infusion system 400 includes a glucosesensor system 410, a control system 412 and an insulin delivery system414. The glucose sensor system 410 (e.g., sensing arrangement 104)generates a sensor signal 416 representative of blood glucose levels 418in the body 420, and provides the sensor signal 416 to the controlsystem 412. The control system 412 receives the sensor signal 416 andgenerates commands 422 that are communicated to the insulin deliverysystem 414. The insulin delivery system 414 receives the commands 422and infuses insulin 424 into the body 420 in response to the commands422.

Generally, the glucose sensor system 410 includes a glucose sensor,sensor electrical components to provide power to the sensor and generatethe sensor signal 416, a sensor communication system to carry the sensorsignal 416 to the control system 412, and a sensor system housing forthe electrical components and the sensor communication system.

Typically, the control system 412 includes controller electricalcomponents and software to generate commands for the insulin deliverysystem 414 based on the sensor signal 416, and a controllercommunication system to receive the sensor signal 416 and carry commandsto the insulin delivery system 414. In preferred embodiments, thecontrol system 412 is housed in the infusion device housing (e.g.,housing 202), however, in alternative embodiments, the control system412 may be housed independently or in another component of an infusionsystem (e.g., the sensing arrangement 104, the CCD 106 and/or thecomputer 108).

The insulin delivery system 414 generally represents the infusion device(e.g., infusion device 102) and any other associated components forinfusing insulin 424 into the body 420 (e.g., the motor 232, the gearassembly 236, and the like). In particular embodiments, the infusiondevice includes infusion electrical components to activate an infusionmotor (e.g., motor 232) according to the commands 422, an infusioncommunication system to receive the commands 422 from the control system412, and an infusion device housing (e.g., housing 202) to hold theinfusion device.

Although not illustrated in FIG. 4, the closed-loop infusion system 400may include or cooperate with a conventional blood glucose meter (e.g.,a finger stick device) that provides measured blood glucose (BG) valuesto the control system 412 and/or to the insulin delivery system 414,such that the glucose sensor system 410 can be calibrated. For example,in certain embodiments, measured BG values are sent to the insulindelivery system 414, which in turn sends a measured BG value, sensorcalibration factor, and calibration time to the control system 412. Thecontrol system 412 can process and analyze the received information todetermine whether or not the infusion system 400 can enter theclosed-loop operating mode. In this regard, the control system 412 maycheck to ensure that the calibration of the glucose sensor system 410 iswithin an acceptable range before allowing the system to enter theclosed-loop mode.

In exemplary embodiments, after entering the closed-loop mode, thecontrol system 412 receives, updates, or otherwise obtains sensorglucose (SG) values, sensor Isig values, calibration factors, “insulindelivered” values, and other data in accordance with a predeterminedschedule, e.g., at five minute intervals. The control system 412determines the desired insulin dose based on the closed-loop algorithmto maintain the patient at a target glucose setpoint, and communicatessuitable control data and instructions to the insulin delivery system414. The insulin delivery system 414 responds to deliver the insulindose specified by the control system 412 to the user.

Referring to FIGS. 1-4, in one or more exemplary embodiments, theglucose sensor system 410 samples or otherwise obtains the sensor signal416, stores the corresponding digital sensor values in a memory and thenperiodically transmits the digital sensor values from the memory to thecontrol system 412. The control system 412 processes the digital sensorvalues and generates commands 422 for the insulin delivery system 414 toactuate the plunger 222 that forces insulin 424 out of the reservoir 206the via a fluid communication path from the reservoir to thesubcutaneous tissue of the user's body 420.

In preferred embodiments, the control system 412 is designed to model apancreatic beta cell (β-cell). In other words, the control system 412commands the infusion device 102, 200 to release insulin 424 into thebody 420 at a rate that causes the insulin concentration in the blood tofollow a similar concentration profile as would be caused by fullyfunctioning human β-cells responding to blood glucose concentrations inthe body 420.

Generally, the in vivo β-cell response to changes in glucose ischaracterized by “first” and “second” phase insulin responses. Thebiphasic insulin response of a β-cell can be modeled using components ofa proportional, plus integral, plus derivative (PID) controller.Accordingly, the control system 412 may be realized as a PID controllersince PID algorithms are stable for a wide variety of non-medicaldynamic systems, and PID algorithms have been found to be stable overwidely varying disturbances and changes in system dynamics.

A proportional component U_(P) and a derivative component U_(D) of thePID controller may be combined to represent a first phase insulinresponse, which lasts several minutes. An integral component U_(I) ofthe PID controller represents a second phase insulin response, which isa steady increase in insulin release under hyperglycemic clampconditions. As described in U.S. patent application Ser. No. 13/966,120,the magnitude of each component's contribution to the insulin responsemay be described by the following equations:

Proportional  Component  Response:  U_(P) = K_(P)(G − G_(B))Integral  Component  Response:  U_(I) = K_(I)∫_(t₀)^(t)(G − G_(B))dt + I_(B), and${{{Derivative}\mspace{14mu}{Component}\mspace{14mu}{Response}\text{:}\mspace{14mu} U_{D}} = {K_{D}\frac{dC}{dt}}},$

Where

U_(P) is the proportional component of the command sent to the insulindelivery system,

U_(I) is the integral component of the command sent to the insulindelivery system,

U_(D) is the derivative component of the command sent to the insulindelivery system,

K_(P) is a proportional gain coefficient,

K_(I) is an integral gain coefficient,

K_(D) is a derivative gain coefficient,

G is a present blood glucose level,

G_(B) is a desired basal glucose level,

t is the time that has passed since the last sensor calibration,

t₀ is the time of the last sensor calibration, and

I_(B) is a basal insulin concentration at to, or can also be describedas U_(I)(t₀).

As described in U.S. patent application Ser. No. 13/966,120, thecomponents of the PID controller can also be expressed in discrete form:

Proportional Component Response: P _(con) ^(n) =K _(P)(SG_(f) ^(n) −G_(sp))

Integral Component Response: I _(con) ^(n) =I _(con) ^(n-1) +K_(I)(SG_(f) ^(n) −G _(sp)); I _(con) ⁰ =I _(b)

Derivative Component Response: D _(con) ^(n) =K _(D) dGdt _(f) ^(n)

Where K_(P), K_(I), and K_(D) are the proportional, integral, andderivative gain coefficients, SG_(f) and dGdt_(f) are the filteredsensor glucose and derivative respectively, and the superscript n refersto discrete time.

An acute insulin response is essential for preventing wide postprandialglycemic excursions. Generally, an early insulin response to a suddenincrease in glucose level results in less total insulin being needed tobring the glucose level back to a desired basal glucose level. This isbecause the infusion of insulin increases the percentage of glucose thatis taken up by the body. Infusing a large amount of insulin to increasethe percentage of glucose uptake while the glucose concentration is highresults in an efficient use of insulin. Conversely, infusing a largeamount of insulin while the glucose concentration is low results inusing a large amount of insulin to remove a relatively small amount ofglucose. In other words, a larger percentage of a big number is morethan a larger percentage of a small number. The infusion of less totalinsulin helps to avoid development of insulin resistance in the user. Aswell, first-phase insulin is thought to result in an early suppressionof hepatic glucose output.

Insulin sensitivity is not fixed and can change dramatically in a bodydepending on the amount of exercise by the body. For example, theinsulin response in an exercise-trained individual may be about one-halfof the insulin response of an NGT individual, but the glucose uptakerate for the exercise-trained individual may be virtually identical tothat of an NGT individual. Thus, an exercise-trained individual may havetwice the insulin sensitivity and half of the insulin response leadingto the same glucose uptake as an NGT individual. Not only is the firstphase insulin response reduced due to the effects of exercise, but thesecond phase insulin response has also been shown to adjust to insulinsensitivity.

In preferred embodiments, a closed loop control system may be used fordelivering insulin to a body to compensate for β-cells that performinadequately. There is a desired basal blood glucose level G_(B) foreach body. The difference between the desired basal blood glucose levelG_(B) and an estimate of the present blood glucose level G is theglucose level error G_(E) that must be corrected.

If the glucose level error G_(E) is positive (meaning that the presentestimate of the blood glucose level G is higher than the desired basalblood glucose level G_(B)) then the control system 412 generates aninsulin delivery command 422 to drive the infusion device 102, 200 toprovide insulin 424 to the body 420. In terms of the control loop,glucose is considered to be positive, and therefore insulin is negative.The sensing arrangement 104, 410 senses the interstitial fluid (ISF)glucose level and generates a sensor signal 416, which, in turn, may befiltered and calibrated to create an estimate of the present bloodglucose level. In particular embodiments, the estimate of the presentblood glucose level G is adjusted with correction algorithms before itis compared to the desired basal blood glucose level G_(B) to calculatea new glucose level error G_(E) to start the loop again.

If the glucose level error G_(E) is negative (meaning that the presentestimate of the blood glucose level is lower than the desired basalblood glucose level G_(B)) then the control system 412 reduces or stopsthe insulin delivery depending on whether the integral componentresponse of the glucose error G_(E) is still positive.

If the glucose level error G_(E) is zero, (meaning that the presentestimate of the blood glucose level is equal to the desired basal bloodglucose level G_(B)) then the control system 412 may or may not issuecommands to infuse insulin depending on the derivative component(whether the glucose level is raising or falling) and the integralcomponent (how long and by how much glucose level has been above orbelow the basal blood glucose level G_(B)).

FIG. 5 depicts a block diagram that illustrates processing modules andalgorithms of an exemplary embodiment of a control system 500 suitablefor use as the control system 412 in the infusion system 400 of FIG. 4,and FIG. 6 is a flow chart that illustrates an exemplary embodiment of acontrol process 600 that may be performed at least in part by thecontrol system 500 to control the insulin delivery system 414 (e.g.,motor 232).

FIG. 5 schematically depicts certain inputs and outputs of the controlsystem 500, where the parallelograms represent the inputs, the ovalsrepresent the outputs, and the rectangles represent the variousfunctional modules of the control system 500. In the context of thisdescription, a “functional module” may be any process, technique,method, algorithm, computer-executable program logic, or the like. Inthis regard, the control system 500 could be realized as any electronicdevice having a processing architecture with at least one processordevice, and at least one memory element that is cooperatively associatedwith the processing architecture. The processing architecture issuitably configured to execute processor-executable instructions storedin the at least one memory element such that the control system 500 canperform the various control operations and methods described in detailherein. Although FIG. 5 conveniently depicts a number of separatefunctional modules, it should be appreciated that the overallfunctionality and configuration of the control system 500 may bealternatively arranged, and that the functions, operations, and tasksdescribed herein may be performed by one or more of the modules asneeded.

The host electronic device that implements the control system 500 may berealized as a monitor device for an insulin infusion device, where themonitor device and the insulin infusion device are two physicallydistinct hardware devices. In another embodiment of the system, the hostelectronic device that implements the control system 500 may be realizedas a portable wireless device, where the portable wireless device andthe insulin infusion device are two physically distinct hardwaredevices. The portable wireless device in this context may be, withoutlimitation: a mobile telephone device; a tablet computer device; alaptop computer device; a portable video game device; a digital mediaplayer device; a portable medical device; or the like. In yet othersystem embodiments, the host electronic device and the insulin infusiondevice are physically and functionally integrated into a single hardwaredevice. In such embodiments, the insulin infusion device will includethe functionality of the control system 500 as presented here.

Certain embodiments of the control system 500 include a plurality ofcooperating functional modules that are designed and configured todetermine the insulin dose to be delivered to keep the patient at thetarget glucose setpoint during an overnight closed-loop operating mode.In this regard, the illustrated embodiment of the control system 500 mayinclude the following functional modules, without limitation: aclosed-loop initiation module 502; a start-up module 504; a proportionalintegral derivative insulin feedback (PID-IFB) control module 506; aninsulin limit module 508; an insulin on board (IOB) compensation module510; an insulin delivery timeout module 512; a model supervisor module514; and a missed transmission module 516.

Referring to FIG. 6, the control process 600 may begin at any time whenit is desired to enter the closed-loop operating mode. Accordingly, thecontrol process 600 may begin in response to a user-initiated command,automatically in response to the detection of operating conditions thatare usually indicative of closed-loop operation (e.g., the user issleeping), or the like. Certain embodiments of the control process 600may begin with one or more system checks (task 602) to confirm whetheror not the system is allowed to enter the closed-loop operating mode.This particular example employs a sensor calibration check beforeallowing the system to proceed to the closed-loop mode. Referring toFIG. 5, the closed-loop initiation module 502 may be involved duringtask 602.

In some embodiments, the closed-loop initiation module 502 may considercertain sensor performance criteria that prevents closed-loopinitiation. Such criteria may include, without limitation: (1) duringstart-up when the calibration is not stable; (2) when the sensorsensitivity changes significantly; (3) when sensors may be calibratedwith a potentially invalid meter reading thereby changing the sensorsensitivity significantly; (4) any other situation that could cause amismatch between the sensor and meter for a number of most recentcalibrations spaced over a designated period of time (e.g., the two mostrecent calibrations).

The illustrated embodiment of the closed-loop initiation module 502receives at least the following items as inputs: a meter (measured) BGvalue 520; at least one sensor calibration factor 522 (i.e., calibrationmeasurements, calibration data, etc.); the sensor Isig value 524; andtimestamp data 526 that indicates the calibration time associated withthe BG value 520 and the sensor calibration factor 522. Some or all ofthis input data may be provided directly or indirectly by the insulindelivery system 414 (see FIG. 4), a translator device, a monitor device,or any device in the closed-loop system. This description assumes that anew sensor calibration factor 522 and new timestamp data 526 may begenerated for each meter BG value 520, wherein the sensor calibrationfactor 522 is associated with the calibration of the glucose sensorsystem 410 (see FIG. 4) that is being used to monitor the patient. Inparticular, the sensor calibration factor may be based on the meter BGvalue 520 and the corresponding sensor Isig value 524.

The closed-loop initiation module 502 analyzes the input data (bothcurrent values and historical values) to determine whether or not thesystem is allowed to enter into the closed-loop mode. For example, theclosed-loop initiation module 502 may: check the period between twoconsecutive calibration timestamp values; compare recent and priorcalibration factor values; and the like. The “outputs” of theclosed-loop initiation module 502 correspond to two operating modes ofthe system. More specifically, the closed-loop initiation module 502controls whether the system remains operating in the open-loop mode 528or whether the system starts the closed-loop mode 530.

Referring to FIG. 6, if the closed-loop mode is not permitted (the “No”branch of query task 604), then the control process 600 operates thesystem such that it remains in the open-loop mode (task 606). On theother hand, if the closed-loop mode is permitted (the “Yes” branch ofquery task 604), then the control process 600 can initiate and start theclosed-loop mode in an appropriate manner (task 608). Referring again toFIG. 5, a correction bolus 532 can be calculated and delivered (ifneeded) to mitigate hyperglycemia at the commencement of the closed-loopmode. This correction bolus 532 serves as an additional safeguard toachieve a target blood glucose level if a measured meter reading isgreater than a threshold value. If the control process 600 determinesthat a correction bolus is required, then an appropriate insulin doseinstruction is generated for execution by the insulin delivery system atthe outset of the closed-loop mode.

Referring to FIG. 5, the start-up module 504 may be called in responseto a determination that the system can proceed to the closed-loopoperating mode. Once the system is in the closed-loop mode, thecontroller retrieves historical data that can be processed and used asdescribed in more detail below. In one or more embodiments, for example,the controller obtains data for the last 24 hours (from the insulindelivery system, from a monitor, or the like). Thereafter, thecontroller retrieves data packets once every sampling period to obtain,without limitation: sensor glucose (SG) values; sensor Isig values;sensor calibration factors; information related to the amount of insulindelivered; information related to manual boluses delivered; and sensorcalibration factors. As explained in more detail below, the receivedinformation can be used in the various safeguards, and to determine thefinal insulin dose.

The start-up module 504 receives sensor glucose (SG) values 540 as aninput, and the functionality of the start-up module 504 may be initiatedin response to the start of the closed-loop mode 530 (this triggermechanism is represented by the dashed arrow 542 in FIG. 5). The SGvalues 540 may be provided directly by the glucose sensor system 410 orindirectly via the insulin delivery system 414, a translator device, orany device in the closed-loop system (see FIG. 4). This descriptionassumes that SG values 540 are received by the start-up module 504 in anongoing manner as they become available. The start-up module 504 mayalso utilize a target glucose setpoint value 544, which may beinternally maintained, generated, and/or provided by the control system500. For the implementation presented here, the target glucose setpointvalue 544 represents a fixed (constant) value that the user can specify(FIG. 5 depicts the target glucose setpoint value 544 in dashed lines toindicate that the value is a user-specified parameter rather than afunctional module or data received by the system).

In certain embodiments, the start-up module 504 calculates a finaltarget glucose value 546, which serves as an input to the PID-IFBcontrol module 506. The final target glucose value 546 enables thesystem to make a smoother transition between open-loop and closed-loopmodes (by gradually adjusting the final target glucose value 546). Thestart-up module 504 may utilize the target glucose setpoint value 544 tocalculate the final target glucose value 546. In this regard, thestart-up module 504 elevates the final target glucose value 546 to thesame level as the sensor glucose value at the start of the closed-loopmode, provided the sensor glucose is above a certain threshold. As timeprogresses, the final target glucose value 546 gradually decreases backto the target glucose setpoint value 544 (usually in approximately twohours). Referring to FIG. 6, the control process 600 calculates thefinal target glucose value (task 610) and continues by calculating anuncompensated insulin infusion rate, PIDRate(n), based at least in parton the final target glucose value (task 612). For this example, thestart-up module 504 may be involved during task 610, and the PID-IFBcontrol module 506 may be involved during task 612.

As an additional safeguard, the insulin limit module 508 cooperates withthe PID-IFB control module 506 to provide an upper insulin limit that iscalculated based on the patient's insulin intake during a designatedfasting period, the patient's fasting blood glucose, and the patient'sinsulin sensitivity. This insulin limit imposes an upper limit to theinsulin delivery rate to avoid over-delivery of insulin by the systemdue to potential sensor error.

The PID-IFB control module 506 may be configured to carry out thecontrol processes described above with reference to FIG. 4. In someembodiments, the PID-IFB control module 506 receives at least thefollowing items as inputs: the SG value 540 (which may be used tocalculate a rate of change value that indicates the rate of change ofthe SG value); the current sensor Isig value 550; the current sensorcalibration factor 552; and an amount of insulin delivered 554. As shownin FIG. 5, the PID-IFB control module 506 may also receive an insulinlimit 559 (e.g., a maximum insulin infusion rate) for the user, ascalculated by the insulin limit module 508. The inputs to the PID-IFBcontrol module 506 may be provided directly or indirectly by the insulindelivery system 414, the glucose sensor system 410, a translator device,a monitor device, and/or any device in the closed-loop system (see FIG.4). The PID-IFB control module 506 is suitably configured to calculatethe insulin infusion rate based on the current and past SG values 540,the SG rate of change, the sensor Isig value 550, the sensor calibrationfactor 552, the final target glucose value 546, and the insulindelivered 554 in order to achieve euglycemia. These (and possibly other)values may be received by the PID-IFB control module 506 in an ongoingmanner as they become available, e.g., in five minute intervals or inaccordance with any desired schedule.

The insulin delivered 554 is a parameter or value that indicates theamount of insulin that has been delivered to the patient by the insulindelivery system. Thus, the insulin delivered 554 may indicate recentboluses (typically by Units) delivered over a period of time. In certainimplementations, the insulin delivered 554 corresponds to the amount ofinsulin delivered in the last sampling time, which may be, withoutlimitation: one minute; five minutes; thirty seconds; or any designatedsampling time. The insulin delivered 554 may also indicate the amount ofinsulin delivered by the delivery system as basal or boluses in anydefined period of time in the past (e.g., the last N hours) or theamount of insulin delivered by the system in the last sampling cycle. Inpractice, the PID-IFB control module 506 (and the IOB compensationmodule 510) may be “initialized” to collect and save historical valuesfor the insulin delivered 554 as needed. Thereafter, the insulindelivered 554 can simply indicate an amount of insulin administered bythe system during the last sampling time period if by a bolus or basalchannels.

As mentioned above, the PID-IFB control module 506 may utilize the upperinsulin limit 559, which is a patient-specific parameter. In certainembodiments, the upper insulin limit 559 may be entered by the user, acaregiver, or the like. Alternatively, the insulin limit module 508 maybe responsible for calculating or otherwise managing the upper insulinlimit 559 if so desired. The upper insulin limit 559 imposes an upperlimit to the insulin delivery rate as an additional safety feature toavoid over-delivery of insulin by the control system 500 due topotential sensor error. Thus, if the PID-IFB control module 506recommends a dose higher than the insulin limit 559, the insulin limit559 will be utilized to constrain the insulin delivered to the insulinlimit value. In addition, implementation of the insulin limit 559 will“freeze” the integral component of the PID to its previous value toprevent integral windup, which can cause continuous integrating of theglucose error until it reaches maximum values. In certain embodiments,the upper insulin limit 559 has a default value set at five times thepatient's basal rate. Hence, if the maximum value is reached, thePID-IFB control algorithm will be fairly aggressive in calculating aninsulin dose. Accordingly, to minimize integral windup, the insulinlimit 559 is fed back to the PID-IFB control module 506 (as depicted inFIG. 5) for use in the next insulin dose calculation.

The PID-IFB control module 506 operates as described previously tocalculate a current insulin dose 558 as an output value (the currentinsulin dose 558 is also referred to herein as the uncompensated insulininfusion rate, PIDRate(n)). In practice, the current insulin dose 558 istypically expressed as an infusion rate (Units/Hour). In the context ofthis description, the current insulin dose 558 may represent aclosed-loop infusion rate that has already been subjected to limiting bythe insulin limit module 508, and which may be subjected to furtheradjustment or compensation by the IOB compensation module 510. Thus, theoutput of the insulin limit module 508 (the upper insulin limit 559)represents a potentially limited insulin dose to be provided by thePID-IFB control module 506—if no limit is imposed, then the insulinlimit 559 has no effect on the output of the PID-IFB control module 506;otherwise, the current insulin dose 558 will be the same as the upperinsulin limit 559. Referring again to FIG. 6, the control process 600may compensate for the insulin “on board” the patient by calculating anadjusted insulin infusion rate, AdjustedRate(n), based at least in parton the uncompensated insulin infusion rate (task 614). For this example,the IOB compensation module 510 may be involved during task 614.

The IOB compensation module 510 receives at least the following items asinputs: the current insulin dose 558; and information regarding manualboluses delivered 560. The manual boluses delivered 560 may be provideddirectly or indirectly by the insulin delivery system 414, a translatordevice, a monitor device, and/or any device in the closed-loop system(see FIG. 4). This description assumes that the manual boluses delivered560 is received by the IOB compensation module 510 in an ongoing manneras it becomes available, e.g., in five minute intervals or in accordancewith any desired schedule. The IOB compensation module 510 is suitablyconfigured to estimate insulin on board based on manual bolusesdelivered, before or during closed-loop operation, in order tocompensate the final infusion rate to help avoid over-delivery ofinsulin by the control system 500. Accordingly, the output of the IOBcompensation module 510 may be a final insulin dose 562 expressed as afinal infusion rate (Units/Hour). The final insulin dose 562 is alsoreferred to herein as the adjusted insulin infusion rate,AdjustedRate(n).

Referring to FIG. 6, the control process 600 uses the adjusted insulininfusion rate, AdjustedRate(n), to control the insulin infusion device,which in turn regulates the delivery of insulin to the body of the user(task 616). In certain embodiments, the adjusted insulin infusion rateis communicated to the insulin infusion device in an appropriate manner(such as wireless data communication). The control process 600 maycontinue as described above in an iterative and ongoing manner tomonitor the condition of the user and deliver insulin as needed withoutuser involvement. That said, if the control process 600 determines thatthe closed-loop operating mode should be terminated (the “Yes” branch ofquery task 618), then the control process 600 causes the system toswitch back to the open-loop mode (task 620). The closed-loop mode maybe ended in response to a user-initiated command, automatically inresponse to the detection of operating conditions that are usuallyindicative of open-loop operation, or the like.

If query task 618 determines that the closed-loop mode should continue(the “No” branch of query task 618), then the control process 600 maycheck whether it is time to perform another iteration of the controlroutine. In other words, the control process 600 may check for the nextsampling time (query task 622). If it is time for the next iteration,then the control process 600 may return to task 610 and repeat thecomputations with the next set of data values. For example, the nextiteration of the control routine may obtain and process the currentvalues of some or all of the following parameters, without limitation:the SG value 540; the SG rate of change; the sensor Isig value 524; theamount of insulin delivered 554; and the manual boluses delivered 560.This allows the control process 600 to adjust the final insulin infusionrate in an ongoing manner in accordance with a predetermined schedule, adesignated sampling rate, or the like.

The insulin delivery timeout module 512 monitors if the patient isreceiving continuous delivery of insulin at the maximum insulin limit orthe minimum allowable infusion of zero Units/Hour for a time specifiedby the controller. Accordingly, the insulin delivery timeout module 512may receive the insulin delivered 554 as an input. If the specified timeis exceeded, the system will trigger a fail-safe alert 566. Otherwise,the system remains in the closed-loop operating mode 568.

Referring back to FIG. 5, the model supervisor module 514 receives atleast the following as inputs: the insulin delivered 554; sensor Isigvalues 550; and one or more sensor calibration factors 552. The inputsto the model supervisor module 514 may be provided directly orindirectly by the insulin delivery system 414, the glucose sensor system410, a translator device, a monitor device, and/or any device in theclosed-loop system (see FIG. 4). The model supervisor module 514 issuitably designed and configured to estimate the user's glucoseconcentration in real time (or substantially real time) based on theinsulin delivered 554, the sensor Isig values 550, and the sensorcalibration factors 552. The sensor calibration factors 552 used by themodel supervisor module 514 are equal to the sensor calibration factors522 used by the closed-loop initiation module 502. That said, theclosed-loop initiation module 502 utilizes the sensor calibrationfactors 522 at one particular time, whereas the model supervisor module514 considers the sensor calibration factors 552 in an ongoing andcontinuous manner during operation in the closed-loop mode. Should themodel-predicted glucose and the sensor glucose values differsignificantly, the system will exit closed loop mode. Accordingly, themodel supervisor module 514 regulates whether the system remains in theclosed-loop mode 574 or switches to the open-loop mode 576.

The missed transmission module 516 is suitably configured to monitor thefollowing, without limitation: the sensor Isig values 550; the SG values540; and the sensor calibration factors 552. More particularly, themissed transmission module 516 continuously monitors to check whetherthe system is receiving data packets that convey the necessaryinformation and input values. For missed data packets totaling less thana lower threshold of time (e.g., 15 minutes), the system remains in theclosed-loop mode, as indicated by block 580 in FIG. 5. During this time,the system will continue to calculate the insulin dose using theclosed-loop control methodology based on the last valid sensor glucosevalue. For missed data packets totaling a time longer than the lowerthreshold and shorter than an upper threshold of time (e.g., 60minutes), the missed transmission module 516 will switch the system to apre-programmed safe basal rate, as indicated by block 582 in FIG. 5. Incertain embodiments, this safe basal rate is defined as half thepatient's overnight basal rate, and this parameter may be programmed bya caregiver or physician. If the missed transmission module 516 startsreceiving data packets while the safe basal rate is being administered,the system will switch back to the closed-loop mode. For missed datapackets totaling more than the upper threshold of time, the system willswitch to the open-loop mode, as indicated by block 584 in FIG. 5. Atthis point, the system will be controlled to deliver a pre-programmedopen-loop overnight basal rate.

To summarize, the control system 500 determines whether to enter intothe closed-loop mode in response to at least the recent meter BG values520, the sensor calibration factors 522, and the calibration timestampdata 526. The control system 500 utilizes the closed-loop initiationmodule 502 to check if the sensor calibration time between the last twocalibration values is within an acceptable range, and whether any changebetween the two calibration values (recent and prior value) isacceptable. If so, the control system 500 will switch the system intothe closed-loop mode. Once the system is in the closed-loop mode, thecontrol system 500 will periodically receive data packets (e.g., everyfive minutes) that include the current SG value 540, the current sensorIsig values 550, the insulin delivered 554, the sensor calibrationfactors 552, and manual boluses delivered 560. In certain embodiments,each of the data packets received by the control system 500 includesdata collected during the previous 24-hour period.

The start-up module 504 utilizes the SG values 540 and the targetglucose setpoint value 544 to calculate the final target glucose value546. In some embodiments, the target glucose setpoint value 544 is setto 120 mg/dL, although other settings could be used if so desired (atypical range of settings may be, for example 70-300 mg/dL). Thisresults in a smoother transition between open-loop and closed-loop modesby gradually adjusting the final target glucose value 546. The finaltarget glucose value 546 is sent to the PID-IFB control module 506 foruse as one input that influences the calculation of the final insulindose 562.

The PID-IFB control module 506 utilizes the final target glucose value546, the current and past SG values 540, the SG rate of change values,and the insulin delivered 554 to determine the insulin infusion rate(the current insulin dose 558) in order to achieve euglycemia. As anadditional safeguard, the upper insulin limit 559 (calculated based onthe patient's insulin intake during a fasting period, fasting bloodglucose, and insulin sensitivity) from the insulin limit module 508 isinput into the control system 500 for each patient to impose an upperlimit to the insulin delivery rate to avoid over-delivery of insulin bythe control system 500. The PID-IFB control module 506 considers theupper insulin limit 559 before sending the current insulin dose 558 tothe IOB compensation module 510, which estimates insulin on board frommanual boluses, before or during closed-loop operation, in order tocalculate the final insulin dose 562. The final insulin dose 562 may becommunicated from the control system 500 directly or indirectly to theinsulin delivery system 414 such that the final insulin dose 562 can bedelivered to the patient during closed-loop operation.

Additional safeguards could be implemented to monitor the system duringclosed-loop operation, such that the system exits the closed-loop modewhen certain criteria are not met. For example, the control system 500may cause the system to exit the closed-loop mode if more than adesignated number of consecutive data packets are missed. This assumesthat the control system 500 usually receives data packets (from theinsulin delivery system 414, from a monitor, from a translation device,or the like) in a continuous manner during closed-loop operation. Thus,if the control system 500 detects that more than a threshold number ofconsecutive data packets are not received as expected, the system willbe commanded to exit the closed-loop mode. This functionality isassociated with the missed transmission module 516, as describedpreviously.

Moreover, the model supervisor module 514 estimates the user's glucoseconcentration in an ongoing manner, based on the insulin delivered 554,the sensor Isig values 550, and the sensor calibration factors 552. Ifthe difference between the model-predicted glucose and the sensorglucose value is greater than a stated threshold, the control system 500may cause the system to exit the closed-loop mode.

As summarized above, the control system 500 employs a number of modulesor functions that cooperate to regulate the delivery of insulin duringclosed-loop operation: the closed-loop initiation module 502; thestart-up module 504; the PID-IFB control module 506; the insulin limitmodule 508; and the IOB compensation module 510. Moreover, the controlsystem 500 may employ a number of modules that perform varioussafeguarding functions during closed-loop operation. These safeguardingmodules may include: the insulin delivery timeout module 512; the modelsupervisor module 514; and the missed transmission module 516.

FIG. 7 depicts another exemplary embodiment of an infusion system 700suitable for use with an infusion device 702, such as the infusiondevice 102 in FIG. 1 or the infusion device 200 of FIG. 2 in conjunctionwith the closed-loop infusion system 400 of FIG. 4 and the closed-loopcontrol process 600 of FIG. 6. In this regard, the illustrated infusionsystem 700 is capable of operating the infusion device 702 to control orotherwise regulate a condition in the body 701 of a user, such as theblood glucose level, to a desired (or target) value or otherwisemaintain the condition within a range of acceptable values. In exemplaryembodiments, a sensing arrangement 704 (e.g., sensing arrangement 104)communicatively coupled to the infusion device 702 is configured tosense, detect, measure or otherwise quantify the condition beingregulated in the body 701 of the user. However, it should be noted thatin alternative embodiments, the condition being regulated by theinfusion system 700 may be correlative to the measured values obtainedby the sensing arrangement 704. That said, for clarity and purposes ofexplanation, the subject matter may be described herein in the contextof the sensing arrangement 704 being realized as an interstitial glucosesensing arrangement that senses, detects, measures or otherwisequantifies the interstitial fluid glucose level, which is beingregulated in the body 701 of the user. As used herein, sensor glucosevalue, sensed glucose value, and variants thereof should be understoodas referring to the quantified interstitial fluid glucose level that iseither output by the sensing arrangement 704 or determined based on theoutput of the sensing arrangement 704.

In exemplary embodiments, the infusion system 700 includes a meter 706that is configured to directly sense, detect, measure or otherwisequantify the condition in the body 701 of the user that is beingregulated by the infusion device 702. For example, the infusion system700 may include a blood glucose meter 706, such as a finger stickdevice, that directly senses, detects, measures or otherwise quantifiesthe user's blood glucose level and outputs or otherwise provides themeasured blood glucose value (e.g., measured BG value 520). In thisregard, the blood glucose meter 706 may provide a reliable measurementof the user's blood glucose level that may be used as a referencemeasurement when calibrating the interstitial glucose sensingarrangement 704 and/or providing closed-loop control of the user's bloodglucose level.

In the illustrated embodiment, the pump control system 720 generallyrepresents the electronics and other components of the infusion device702 that control operation of the fluid infusion device 702 according toa desired infusion delivery program in a manner that is influenced bysensor data pertaining to a condition of a user (e.g., the user'scurrent glucose level) received from the glucose sensing arrangement 704and/or in a manner that is dictated by the user. To support closed-loopcontrol, the pump control system 720 maintains, receives, or otherwiseobtains a desired value for a condition in the body 701 of the user tobe regulated (e.g., a target or commanded glucose value). For example,the infusion device 702 may store or otherwise maintain the target valuein a data storage element accessible to the pump control system 720.Alternatively, the target value may be received from an externalcomponent (e.g., CCD 106 and/or computer 108) or be input by a user viaa user interface element 708 associated with the infusion device 702.

As described in greater detail below in the context of FIGS. 9-10, inexemplary embodiments, the pump control system 720 is coupled to one ormore user interface elements 708 to receive or otherwise obtain alertconfiguration information for the user associated with the infusiondevice 702 and generate or otherwise provide notifications to the userin accordance with that user's alert configuration while operating theinfusion device 702 to provide closed-loop control of the user's bloodglucose level. In this regard, to receive the user's alert configurationinformation, the one or more user interface element(s) 708 include atleast one input user interface element, such as, for example, a button,a keypad, a keyboard, a knob, a joystick, a mouse, a touch panel, atouchscreen, a microphone or another audio input device, and/or thelike. Similarly, to generate user notifications according to the user'salert configuration information, the one or more user interfaceelement(s) 708 include at least one output user interface element, suchas, for example, a display element (e.g., a light-emitting diode or thelike), a display device (e.g., a liquid crystal display or the like), aspeaker or another audio output device, a haptic feedback device, or thelike. It should be noted that although FIG. 7 depicts the user interfaceelement(s) 708 as being separate from the infusion device 702, inpractice, one or more of the user interface element(s) 708 may beintegrated with the infusion device 702. Additionally, in variousembodiments, one or more of the user interface element(s) 708 may beintegrated in another component of the infusion system 700 (e.g., theCCD 106, the computer 108, or the like) that is communicatively coupledto the infusion device 702 and/or the pump control system 720 asdescribed above in the context of FIG. 1. In such embodiments, the pumpcontrol system 720 may support remote user notifications (e.g., textmessages, e-mails, or the like) that are provided to the user or otherindividuals designated by the user as desired by the user and indicatedby the user's alert configuration information.

In exemplary embodiments, the pump control system 720 stores orotherwise maintains the user's alert configuration information andaccesses the user's alert configuration information in conjunction withproviding closed-loop control of the user's blood glucose as describedabove in the context of FIGS. 4-6. In this regard, when the pump controlsystem 720 detects or otherwise identifies a potential alert condition(e.g., an insulin delivery timeout, a deviation in an estimated orpredicted sensor glucose value relative to the current sensor glucosevalue from the glucose sensing arrangement 704, a missed transmission,or the like) while providing closed-loop control, the pump controlsystem 720 consults the user's alert configuration information todetermine whether the user wants to be notified (or the user wantsothers to be notified) of that condition, and if so, the manner in whichthe user wants to be notified of that condition. Thereafter, the pumpcontrol system 720 automatically generates or otherwise provides thedesired user notification(s) for the detected alert condition to theuser via the one or more user interface element(s) 708. For example, auser's alert configuration information may indicate that the user wouldlike to be provided with only a visual notification (e.g., a flashinglight or another indicator) when the missed transmission module 516detects missed data packets totaling a time shorter than an upperthreshold of time, and that the user would like to be provided with bothauditory and haptic feedback when the missed transmission module 516detects missed data packets totaling a time longer than the upperthreshold of time that results in transitioning to the open-loopovernight basal rate delivery mode. Thus, when the pump control system720 detects missed transmissions for a duration of time that is lessthan the upper threshold, the pump control system 720 may illuminate orotherwise operate a display element 708 to provide a visual notificationof the missed transmission to the user, and thereafter operate an audiooutput device 708 and a haptic feedback device 708 to provide auditoryand haptic notifications to the user upon detecting that the missedtransmissions exceed the upper threshold. In this manner, the user maybe apprised of different alert conditions in different manners, and themanner in which one user is notified of the various different alertconditions may be different from other users. Thus, the alertconfiguration information may be understood as being user-specific, inthat it may be unique to the user associated with the infusion device702.

As described in greater detail below in the context of FIGS. 9-10, inresponse to a user notification generated by the pump control system720, the user may respond or otherwise interact with the pump controlsystem 720 and/or the infusion device 702 to provide a user response tothe notification that influences subsequent operation of the infusiondevice 702. For example, in response to a user notification, the usermay operate the blood glucose meter 706 to provide an updated (or new)blood glucose measurement to the pump control system 720 which may beutilized as a blood glucose reference measurement for recalibrating theglucose sensing arrangement 704 and/or reinitializing the closed-loopcontrol. In other embodiments, the user may manipulate or otherwiseoperate an input user interface element 708 to modify or otherwiseadjust settings or other configuration information for the infusiondevice 702 that influences subsequent operation of the infusion device702 (e.g., changing the safe basal rate, the overnight basal rate, orthe like). Thus, not only may the user notification be generated in auser-specific manner, but each individual user may respond to aparticular user notification in a different manner based on that user'spersonal preferences or other factors, thereby allowing the user tofurther personalize or otherwise influence the manner in which theclosed-loop control is subsequently implemented by the infusion device702 and/or the pump control system 720.

Still referring to FIG. 7, the infusion device 702 includes a motorcontrol module 712 coupled to a motor 732 (e.g., motor 232) that isoperable to displace a plunger 722 (e.g., plunger 222) in a reservoir(e.g., reservoir 206) and provide a desired amount of fluid to the body701 of a user. In this regard, displacement of the plunger 722 resultsin the delivery of a fluid that is capable of influencing the conditionin the body 701 of the user to the body 701 of the user via a fluiddelivery path. A motor driver module 714 is coupled between an energysource 718 and the motor 732. The motor control module 712 is coupled tothe motor driver module 714, and the motor control module 712 generatesor otherwise provides command signals that operate the motor drivermodule 714 to provide current (or power) from the energy source 718 tothe motor 732 to displace the plunger 722 in response to receiving, froma pump control system 720, a delivery command (or dosage command)indicative of the desired amount of fluid to be delivered.

In exemplary embodiments, the energy source 718 is realized as a batteryhoused within the infusion device 702 (e.g., within housing 202) thatprovides direct current (DC) power. In this regard, the motor drivermodule 714 generally represents the combination of circuitry, hardwareand/or other electrical components configured to convert or otherwisetransfer DC power provided by the energy source 718 into alternatingelectrical signals applied to respective phases of the stator windingsof the motor 732 that result in current flowing through the statorwindings that generates a stator magnetic field and causes the rotor ofthe motor 732 to rotate. The motor control module 712 is configured toreceive or otherwise obtain a delivery command (or commanded dosage)from the pump control system 720, convert the delivery command to acommanded translational displacement of the plunger 722, and command,signal, or otherwise operate the motor driver module 714 to cause therotor of the motor 732 to rotate by an amount that produces thecommanded translational displacement of the plunger 722. For example,the motor control module 712 may determine an amount of rotation of therotor required to produce translational displacement of the plunger 722that achieves the commanded dosage received from the pump control system720.

Based on the current rotational position (or orientation) of the rotorwith respect to the stator that is indicated by the output of the rotorsensing arrangement 716, the motor control module 712 determines theappropriate sequence of alternating electrical signals to be applied tothe respective phases of the stator windings that should rotate therotor by the determined amount of rotation from its current position (ororientation). In embodiments where the motor 732 is realized as a BLDCmotor, the alternating electrical signals commutate the respectivephases of the stator windings at the appropriate orientation of therotor magnetic poles with respect to the stator and in the appropriateorder to provide a rotating stator magnetic field that rotates the rotorin the desired direction. Thereafter, the motor control module 712operates the motor driver module 714 to apply the determined alternatingelectrical signals (e.g., the command signals) to the stator windings ofthe motor 732 to achieve the desired delivery of fluid to the user. Whenthe motor control module 712 is operating the motor driver module 714,current flows from the energy source 718 through the stator windings ofthe motor 732 to produce a stator magnetic field that interacts with therotor magnetic field. In some embodiments, after the motor controlmodule 712 operates the motor driver module 714 and/or motor 732 toachieve the commanded dosage, the motor control module 712 ceasesoperating the motor driver module 714 and/or motor 732 until asubsequent delivery command is received. In this regard, the motordriver module 714 and the motor 732 enter an idle state during which themotor driver module 714 effectively disconnects or isolates the statorwindings of the motor 732 from the energy source 718. In other words,current does not flow from the energy source 718 through the statorwindings of the motor 732 when the motor 732 is idle, and thus, themotor 732 does not consume power from the energy source 718 in the idlestate, thereby improving efficiency.

Depending on the embodiment, the motor control module 712 may beimplemented or realized with a general purpose processor, amicroprocessor, a controller, a microcontroller, a state machine, acontent addressable memory, an application specific integrated circuit,a field programmable gate array, any suitable programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof, designed to perform the functions described herein.Furthermore, the steps of a method or algorithm described in connectionwith the embodiments disclosed herein may be embodied directly inhardware, in firmware, in a software module executed by the motorcontrol module 712, or in any practical combination thereof. Inexemplary embodiments, the motor control module 712 includes orotherwise accesses a data storage element or memory, including any sortof random access memory (RAM), read only memory (ROM), flash memory,registers, hard disks, removable disks, magnetic or optical massstorage, or any other short or long term storage media or othernon-transitory computer-readable medium, which is capable of storingprogramming instructions for execution by the motor control module 712.The computer-executable programming instructions, when read and executedby the motor control module 712, cause the motor control module 712 toperform the tasks, operations, functions, and processes describedherein.

It should be understood that FIG. 7 depicts a simplified representationof the infusion device 702 for purposes of explanation and is notintended to limit the subject matter described herein in any way. Inthis regard, depending on the embodiment, some features and/orfunctionality of the motor control module 712 may implemented by orotherwise integrated into the pump control system 720, or vice versa.Furthermore, some of the features and/or functionality of the pumpcontrol system 720 described herein may be implemented by a remotecomputing device that is physically distinct and/or separate from theinfusion device 702 (e.g., the CCD 106, the computer 108, and/or anothermonitor device) and communicatively coupled to the motor control module712, the sensing arrangement 704 and/or the blood glucose meter 706.Additionally, although FIG. 7 depicts the glucose sensing arrangement704 as being physically separate and distinct from the infusion device702, in alternative embodiments, the glucose sensing arrangement 704 maybe integrated into or otherwise implemented by the infusion device 702(e.g., by providing the glucose sensing arrangement 704 within thehousing 202).

FIG. 8 depicts an exemplary embodiment of a pump control system 800suitable for use as the pump control system 720 in FIG. 8 in accordancewith one or more embodiments. The illustrated pump control system 800includes, without limitation, a pump control module 802, acommunications interface 804, and data storage elements 806, 808. Itshould be understood that FIG. 8 is a simplified representation of pumpcontrol system 800 for purposes of explanation and is not intended tolimit the subject matter described herein in any way. In this regard,although FIG. 8 depicts the data storage elements 806, 808 as beingdistinct or otherwise separate from one another, in practice, the datastorage elements 806, 808 may be realized using a single integrated datastorage element.

The control module 802 generally represents the hardware, circuitry,logic, firmware and/or other components of the pump control system 800configured to determine delivery (or dosage) commands for operating amotor using closed-loop control and perform various additional tasks,operations, functions and/or operations described herein. Depending onthe embodiment, the control module 802 may be implemented or realizedwith a general purpose processor, a microprocessor, a controller, amicrocontroller, a state machine, a content addressable memory, anapplication specific integrated circuit, a field programmable gatearray, any suitable programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof, designed to perform the functions described herein.Furthermore, the steps of a method or algorithm described in connectionwith the embodiments disclosed herein may be embodied directly inhardware, in firmware, in a software module executed by the controlmodule 802, or in any practical combination thereof.

The communications interface 804 generally represents the hardware,circuitry, logic, firmware and/or other components configured to supportcommunications to/from the pump control system 800. For example,referring to FIGS. 1 and 7, the communications interface 804 may includeor otherwise be coupled to one or more transceiver modules capable ofsupporting wireless communications between the infusion device 702 andanother device (e.g., one or more of the sensing arrangements 104, 704,the blood glucose meter 706, the CCD 106, the computer 108, or thelike).

In exemplary embodiments, the data storage element (or memory) 806 isrealized as any sort of random access memory (RAM), read only memory(ROM), flash memory, registers, hard disks, removable disks, magnetic oroptical mass storage, short or long term storage media, or any othernon-transitory computer-readable medium capable of storing programminginstructions for execution by the control module 802. Thecomputer-executable programming instructions, when read and executed bythe control module 802, cause the control module 802 to perform thetasks, operations, functions, and processes described in greater detailbelow. In this regard, the control scheme or algorithm implemented bythe control module 802 may be realized as control application code thatis stored or otherwise maintained in the memory 806 and executed by thecontrol module 802 to implement or otherwise provide one or more of theclosed-loop PID control components in software. For example, the controlapplication code may be executed by the control module 802 to implementor otherwise provide one or more of the components or functional modulesof the control system 500 of FIG. 5 and implement the control process600 of FIG. 6.

As described above with reference to FIGS. 4-7, in exemplaryembodiments, the control module 802 obtains a target glucose value forthe user associated with the infusion device 702, obtains a sensedglucose value from the glucose sensing arrangement 704, and performs PIDcontrol to regulate the measured value to the target value. For example,the control module 802 may include or otherwise implement a summationblock that determines a difference between the target glucose value andthe sensed glucose value, a proportional gain block that multiplies thedifference by a proportional gain coefficient, integration and gainblocks that multiply the integrated difference by an integration gaincoefficient, and derivative and gain blocks that multiply the derivativeof the difference by a derivative gain coefficient.

In the illustrated embodiment of FIG. 8, the data storage element 808generally represents the hardware, circuitry and/or other components ofthe pump control system 720 that are configured to store the closed-loopcontrol information for the control scheme implemented by the controlmodule 802. In this regard, the data storage element 808 may store orotherwise maintain the control parameters for the closed-loop control(e.g., the target glucose value, the proportional gain coefficient, theintegration gain coefficient, the derivative gain coefficient, insulindelivery limits, threshold values, and the like). Additionally, the datastorage element 808 may store or otherwise maintain the notificationparameters for the user's alert configuration information, which definesthe manner in which user notifications should be provided whileoperating the infusion device 702 in accordance with the closed-loopcontrol parameters. In a similar manner as described above in thecontext of the memory 806, the data storage element 808 may be realizedas any sort of RAM, ROM, flash memory, registers, hard disks, removabledisks, magnetic or optical mass storage, short or long term storagemedia, or any other non-transitory computer-readable medium. That said,in exemplary embodiments, the data storage element 808 is realized aplurality of registers associated with the control and notificationparameters for the closed-loop, and accordingly, the data storageelement 808 may alternatively be referred to herein as the parameterregisters.

FIG. 9 depicts an exemplary alerting process 900 suitable forimplementation by a control system associated with a fluid infusiondevice to automatically provide user notifications in a user-specific(or user-configurable) manner while providing closed-loop control of thecondition in the body of the user that is influenced by the fluiddelivered by the fluid infusion device. The various tasks performed inconnection with the alerting process 900 may be performed by hardware,firmware, software executed by processing circuitry, or any combinationthereof. For illustrative purposes, the following description refers toelements mentioned above in connection with FIGS. 1-8. In practice,portions of the alerting process 900 may be performed by differentelements of an infusion system, such as, for example, the infusiondevice 702, the glucose sensing arrangement 704, the blood glucose meter706, the user interface element(s) 708, and/or the pump control system720 in the infusion system 700 of FIG. 7. It should be appreciated thatthe alerting process 900 may include any number of additional oralternative tasks, the tasks need not be performed in the illustratedorder and/or the tasks may be performed concurrently, and/or thealerting process 900 may be incorporated into a more comprehensiveprocedure or process having additional functionality not described indetail herein. Moreover, one or more of the tasks shown and described inthe context of FIG. 9 could be omitted from a practical embodiment ofthe alerting process 900 as long as the intended overall functionalityremains intact.

In exemplary embodiments, the alerting process 900 initializes orotherwise begins by receiving or otherwise obtaining alert configurationinformation for a user and storing or otherwise maintaining the user'salert configuration information (tasks 902, 904). In this regard, theuser or patient associated with the infusion device 702 or anotherindividual (e.g., a doctor, nurse, caregiver, or the like) maymanipulate an input user interface element 708 to interact with the pumpcontrol system 720 to configure the alerts or notifications to begenerated by the pump control system 720 during closed-loop control ofthe user's glucose level. In practice, the pump control system 720 maygenerate or otherwise provide one or more graphical user interface (GUI)displays on a display device associated with the infusion device 702(which may be a user interface element 708 integrated with the infusiondevice 702 or part of another device 106, 108 communicatively coupled tothe infusion device 102, 702) that include a menu or list of the variousdifferent alertable conditions that may be detected by the pump controlsystem 720 during closed-loop control of the user's blood glucose level.For example, as described above in the context of FIGS. 5-6, the pumpcontrol system 720 may be configured to detect when the infusion device702 provides continuous delivery of insulin at a maximum insulin limitfor greater than a threshold amount of time, when the infusion device702 provides delivery of insulin that is less than or equal to a minimumallowable infusion of zero for greater than a threshold amount of time,when an estimated (or model-predicted) glucose differs from the sensorglucose value obtained from the glucose sensing arrangement 704 isgreater than a threshold value, when the pump control system 720 and/orthe infusion device 702 fails to receive data packets from the glucosesensing arrangement 704, when the closed-loop mode should be exited(e.g., when a closed-loop control time limit has been reached), and thelike.

In exemplary embodiments, the GUI display(s) provided by the pumpcontrol system 720 include GUI elements (e.g., buttons, checkboxes, orthe like) that are selectable by the user to indicate or otherwiseidentify the conditions that the user would like to receivenotifications of, along with GUI elements that are selectable by theuser to indicate or otherwise identify the type of notification that theuser would like to receive when that respective condition is detected bythe pump control system 720. For example, the user may manipulate theGUI elements to indicate that the user would like to receive a visualnotification when the missed transmission module 516 and/or the pumpcontrol system 720 detects missed data packets from the glucose sensingarrangement 704 for a duration of time that is less than a lowerthreshold of amount time (e.g., 15 minutes), both a visual and a hapticnotification when the missed transmission module 516 and/or the pumpcontrol system 720 detects missed data packets from the glucose sensingarrangement 704 for a duration of time that is greater than the lowerthreshold of amount time but less than an upper threshold amount of time(e.g., 60 minutes), and visual, haptic, and auditory notifications whenthe missed transmission module 516 and/or the pump control system 720detects missed data packets from the glucose sensing arrangement 704 fora duration of time that is greater than the upper threshold amount oftime. In some embodiments, the GUI display(s) provided by the pumpcontrol system 720 may include GUI elements that allow the user to setor otherwise adjust the thresholds used by the pump control system 720to detect the various alertable conditions. For example, a user mayincrease or decrease the threshold for a particular condition based onthe user's personal preferences with respect to when and/or howfrequently the user would like to be notified. Additionally, the usermay provide configuration information that defines whether or not aparticular user notification should be repeated when a user response isnot received (e.g., to ensure that the user has received thenotification), and if so, the frequency and/or manner in which the usernotification should be repeated.

In embodiments where the pump control system 720 supports remotenotifications (e.g., via text message or other short messaging service,e-mail, or the like), the GUI display(s) provided by the pump controlsystem 720 may include GUI elements that allow the user to provide thedesired destination address for the remote notification (e.g., the phonenumber, e-mail address, or the like) that will be provided for theparticular detected condition. In this regard, remote notifications maybe sent to other individuals in different situations, as desired by theuser, so that other individuals may be apprised of the user's physicalcondition and aid or otherwise assist the user, as needed. Afterselecting the desired GUI elements to indicate the conditions that theuser would like to be alerted of, the types and/or numbers ofnotifications that the user would like to receive for those selectedconditions, and/or any user-configured thresholds for those selectedconditions, the user may manipulate another GUI element to confirm orotherwise save his or her alert configuration information.

In exemplary embodiments, after receiving selection or indication ofwhich conditions that the user would like to be notified of along withthe types of notifications that the user would like to receive for thoserespective conditions, the pump control system 720 stores or otherwisemaintains that user-specific alert configuration information forreference while providing closed-loop control of the user's bloodglucose level. For example, the pump control system 720 may store orotherwise maintain data or information in the parameter registers 808that corresponds to the selected GUI elements on the GUI displayprovided by the pump control system 720. Thus, the data or informationstored in the parameter registers 808 define the manner in which theuser associated with the infusion device 702 would like to be notifiedduring implementation of the closed-loop mode.

Still referring to FIG. 9, the alerting process 900 continues byoperating the fluid infusion device to provide closed-loop control ofthe user's glucose level and detecting or otherwise identifying an alertcondition while providing the closed-loop control (tasks 906, 908). Asdescribed above in the context of FIGS. 5-6, the pump control system 720may initiate the control process 600 in response to a user-initiatedcommand, automatically in response to the detection of operatingconditions that are usually indicative of closed-loop operation (e.g.,that the user is sleeping), or otherwise determining that it is desiredto enter the closed-loop operating mode. Once in the closed-loop mode,the pump control system 720 utilizes glucose measurement data (e.g., thecurrent SG value 540, the current sensor Isig value 550, and the like)received from the glucose sensing arrangement 704 to determine a sensorglucose value and applies the PID gain coefficients to the differencebetween the sensor glucose value and a target glucose value to obtaindelivery commands provided to the motor control module 712 for operatingthe motor 732. While in the closed-loop mode, the pump control system720 implements or otherwise provides a number of modules 512, 514, 516that monitor for alertable conditions, as described above.

In response to detecting an alert condition, the alerting process 900generates or otherwise provides one or more user notifications inaccordance with the user's alert configuration information for thatparticular type of alert condition (task 910). In this regard, when amodule 512, 514, 516 of the pump control system 720 detects an alertcondition, the pump control system 720 accesses the user's alertconfiguration information stored in the parameter registers 808 todetermine whether the user has selected or otherwise indicated that heor she would like to be notified of that detected condition, along withthe manner in which the user would like to be notified. When the pumpcontrol system 720 determines the user would like to be notified of thedetected condition, the pump control system 720 automatically generatesor otherwise provides one or more user notifications in accordance withthe user's alert configuration information for that detected condition.For example, if the user's alert configuration information indicatesthat the user would like to receive an auditory notification when themodel supervisor module 514 detects the estimated blood glucose differsfrom the measured sensor glucose value obtained via the glucose sensingarrangement 704 by more than a threshold value, the pump control system720 automatically operates a speaker or other audio output interfaceelement 708 associated with the infusion device 702 to provide anauditory notification (or indication) of the deviation between theestimated blood glucose value and the measured sensor glucose value inresponse to the model supervisor module 514 detecting the deviation. Forremote notifications (e.g., text messages, e-mails, or the like), thepump control system 720 may automatically initiate transmission of aremote notification to the destination address(es) stored in theparameter registers 808. In some embodiments, the remote notificationmay identify, describe, or otherwise detail the alerted condition thatwas detected by the pump control system 720 to provide guidance to therecipient or otherwise aid the recipient's understanding of the alertedcondition.

Still referring to FIG. 9, in accordance with one or more embodiments,the alerting process 900 continues by providing alternative control ofthe user's glucose level based on the detected alert condition untilreceiving a response to the generated user notification(s), andthereafter provides control of the user's glucose level in a manner thatis influenced by or otherwise based on the received user response (tasks912, 914, 916). In this regard, as described above in the context ofFIGS. 5-6, after a module 512, 514, 516 of the pump control system 720detects a particular alertable condition, the pump control system 720may provide alternative control of the glucose level in lieu of theclosed-loop control, such as, for example, by generating deliverycommands that operate the motor 732 to provide a pre-programmed safebasal rate (e.g., block 582) or a pre-programmed open-loop overnightbasal rate (e.g., blocks 976, 984) based on the particular conditiondetected. In exemplary embodiments, the pump control system 720automatically generates or otherwise provides user notifications toapprise the user that the closed-loop control mode has been exited andan alternative control mode is being implemented in accordance with theuser's alert configuration information. For example, the pump controlsystem 720 may automatically generate a visual notification on a displaydevice that indicates that the closed-loop control mode has beensuspended, terminated, or otherwise exited and identifies thealternative control mode that is currently being implemented by the pumpcontrol system 720. In some embodiments, the user may also configure thepump control system 720 to automatically generate notifications whileimplementing the alternative control mode in a similar manner asdescribed herein in the context of the closed-loop control mode.

As described in greater detail below in the context of FIG. 10, inresponse to receiving a notification, the user may manipulate a userinterface element 708 associated with the infusion device 702 and/or theblood glucose meter 706 to provide a response to the pump control system720 and/or the infusion device 702 in an attempt to resume theclosed-loop control mode and/or override the alternate control modebeing provided by the pump control system 720. Based on the responsereceived from the user, the pump control system 720 proceeds withoperating the infusion device 702 and/or the motor 732 to deliver fluidto the user in a manner that is influenced by the received userresponse. For example, when the user operates the blood glucose meter706 to obtain a new blood glucose measurement value that is provided tothe pump control system 720 and/or the infusion device 702 toreinitialize the closed-loop control mode (e.g., when the usernotification was generated by the insulin delivery timeout module 512based on the insulin delivery exceeding and/or failing to meet adelivery limit or by the model supervisor module 514 based on thedeviation between the estimated blood glucose value and the measuredsensor blood glucose value), the pump control system 720 and/or theinfusion device 702 may reinitialize the closed-loop control mode andresume providing closed-loop control based at least in part on the newblood glucose measurement value. In other embodiments, the user maysimply manipulate a user interface element 708 to attempt cause the pumpcontrol system 720 to reinitialize the closed-loop control mode (e.g.,after replacing the glucose sensing arrangement 704 or manipulating theglucose sensing arrangement 704 and/or the infusion device 702 in amanner that is intended to improve transmissions when the usernotification is generated by the missed transmission module 516 based onmissed transmissions), whereby the pump control system 720 and/or theinfusion device 702 may reinitialize the closed-loop control mode andresume providing closed-loop control based on resumed transmissions withthe glucose sensing arrangement 704. In yet other embodiments, the usermay manipulate a user interface element 708 to cause the pump controlsystem 720 to transition to a manual (or user-controlled) operatingmode.

In this manner, the user response allows the pump control system 720 toproceed with providing control of the user's glucose level in auser-specific manner, based on the user's response to the particularuser notifications generated by the pump control system 720. Forexample, some users may choose to simply allow the pump control system720 to provide open-loop control of the glucose level, while other usersmay choose to be more proactive with attempts to reinitialize theclosed-loop control mode, while other users may choose to simply disableany automatic control of insulin delivery and revert to a manualoperating mode. Even among proactive users, some users may attempt toreinitialize the closed-loop control using solely a new blood glucosemeasurement value from the blood glucose meter 706, while other usersmay also replace the glucose sensing arrangement 704 (or a batteryassociated therewith) before attempting to reinitialize the closed-loopcontrol. Thus, not only may each individual user be alerted in his orher own uniquely desired manner in accordance with his or heruser-specific alert configuration scheme, but each individual user alsocan individually determine how to respond to alert notifications,thereby enabling the pump control system 720 to proceed after thenotifications in a more personalized or user-configurable manner basedon the response received from the user.

FIG. 10 depicts an exemplary adaptive response process 1000 suitable forimplementation in conjunction with the alerting process 900 of FIG. 9(e.g., task 916) to adjust or otherwise modify the manner in which afluid infusion device is being controlled based on a response receivedfrom a user. The various tasks performed in connection with the adaptiveresponse process 1000 may be performed by hardware, firmware, softwareexecuted by processing circuitry, or any combination thereof. Forillustrative purposes, the following description refers to elementsmentioned above in connection with FIGS. 1-8. In practice, portions ofthe adaptive response process 1000 may be performed by differentelements of an infusion system, such as, for example, the infusiondevice 702, the glucose sensing arrangement 704, the blood glucose meter706, the user interface element(s) 708, and/or the pump control system720 in the infusion system 700 of FIG. 7. It should be appreciated thatthe adaptive response process 1000 may include any number of additionalor alternative tasks, the tasks need not be performed in the illustratedorder and/or the tasks may be performed concurrently, and/or theadaptive response process 1000 may be incorporated into a morecomprehensive procedure or process having additional functionality notdescribed in detail herein. Moreover, one or more of the tasks shown anddescribed in the context of FIG. 10 could be omitted from a practicalembodiment of the adaptive response process 1000 as long as the intendedoverall functionality remains intact.

In exemplary embodiments, the adaptive response process 1000 begins byreceiving or otherwise obtaining an updated (or new) blood glucosemeasurement for the user from a blood glucose meter (task 1002). In thisregard, an updated (or new) measurement for use as the reference meterBG value 520 is obtained using the blood glucose meter 706. For example,in response to a user notification generated by the pump control system720, the user may manipulate or otherwise operate the blood glucosemeter 706 to obtain a new blood glucose measurement value and transmitthe new blood glucose measurement value to the pump control system 720to reinitialize the closed-loop control mode. In exemplary embodiments,the pump control system 720 stores or otherwise maintains the updatedblood glucose reference measurement value, for example, by overwritingthe existing meter BG value 520 with the updated (or new) blood glucosemeasurement value.

The adaptive response process 1000 continues by receiving or otherwiseobtaining a recent interstitial fluid glucose measurement anddetermining whether the interstitial fluid glucose measurement matchesor otherwise corresponds to the new meter blood glucose measurementvalue (tasks 1004, 1006). Depending on the embodiment, the pump controlsystem 720 may obtain the most recent sensor glucose value (e.g., from adata storage element 806, 808) or wait until an updated (or new) sensorglucose value is transmitted by the glucose sensing arrangement 704 oris otherwise available. Thereafter, the pump control system 720 comparesthe most recent sensor glucose value 540 to the updated (or new) meterBG value 520 to determine whether the most recent sensor glucose value540 is substantially equal to the updated meter BG value 520. In oneembodiment, the pump control system 720 determines the most recentsensor glucose value 540 is substantially equal to the updated meter BGvalue 520 when the most recent sensor glucose value 540 is within thirtypercent of the updated meter BG value 520 when the updated meter BGvalue 520 is greater than 80 mg/dL, or alternatively, when the mostrecent sensor glucose value 540 is within 15 mg/dL of the updated meterBG value 520 when the updated meter BG value 520 is less than 80 mg/dL.

When the new meter BG value is substantially equal to the most recentsensor glucose value, the adaptive response process 1000 determines thatthe meter and interstitial glucose measurement values match and allowsthe closed-loop control mode to be reinitialized using the new meter BGmeasurement value (task 1008). In this regard, the closed-loopinitiation module 502 of the pump control system 720 references orotherwise utilizes the updated meter BG value 520 when determiningwhether the closed-loop mode can be initiated in conjunction with thecontrol process 600 of FIG. 6.

In one or more exemplary embodiments, after confirming the updated meterBG value 520 and the sensor glucose value 540 match, the pump controlsystem 720 also resets one or more counters, timers, or the like used toidentify alert conditions upon reinitialization of the closed-loop mode.For example, the insulin delivery timeout module 512 may reset anytimers or counters used to monitor the insulin delivery rate, so thatthe original limits or thresholds apply for the subsequent instantiationof the closed-loop mode. Thus, if the alert condition that triggered theuser notification was detected by the insulin delivery timeout module512, after confirming that the sensor glucose value 540 is accurate orotherwise matches the updated meter BG value 520, the closed-loopcontrol mode may be allowed to resume continuous delivery of insulin atan insulin delivery limit for the original time limit. For example, theinsulin delivery timeout module 512 may detect an alert condition when amaximum insulin delivery rate limit is continuously provided for a threehour time limit, and in response, the pump control system 720 maygenerate a user notification in accordance with the user's alertconfiguration information that indicates to the user that the maximumcontinuous insulin delivery rate limit has been met. In response, afterthe user manipulates the blood glucose meter 706 to provide an updatedmeter BG value 520 that confirms the sensor glucose value 540 isaccurate, the insulin delivery timeout module 512 is reset orreinitialized so that the subsequent iteration of the closed-loopcontrol mode may also be allowed to continuously provide the maximuminsulin delivery rate for three hours before another alert condition isdetected. In some embodiments, other limitations on the closed-loop modeare maintained unchanged upon reinitiating the closed-loop mode. Forexample, if the closed-loop mode is limited in duration to only eighthours in a twenty-four hour window, the counters and/or timers thatmonitor the duration in which closed-loop mode has been utilized duringthe course of the preceding twenty-four hours are not reset to preventthe closed-loop mode from being implemented for more than eight hours ina twenty-four hour window.

Still referring to FIG. 10, when the adaptive response process 1000determines that the new meter BG value does not match the sensor glucosevalue, the adaptive response process 1000 determines whether thedifference between the new meter BG value and the most recent sensorglucose value indicates an anomalous condition of the interstitialglucoses sensing arrangement (task 1010). In one or more embodiments,the pump control system 720 calculates or otherwise determines a sensorcalibration factor for the glucose sensing arrangement 704 based on theupdated meter BG value 520 and the most recent sensor Isig value 524,and identifies an anomalous condition when that sensor calibrationfactor is not within an acceptable range of values for the glucosesensing arrangement 704. For example, the pump control system 720 mayidentify an anomalous condition when the sensor calibration factor isless than 2.5 or greater than 12. In some embodiments, the pump controlsystem 720 may identify an anomalous condition when a difference betweenthe updated meter BG value 520 and the most recent sensor glucose value540 is greater than a threshold value indicative of an anomalouscondition.

When the adaptive response process 1000 determines that an anomalouscondition of the interstitial glucose sensing arrangement does notexist, the adaptive response process 1000 proceeds by recalibrating theinterstitial glucose sensing arrangement using the new meter BG value(task 1012). In this regard, the pump control system 720 may calculateor otherwise determine an updated (or new) sensor calibration factor 522for the glucose sensing arrangement 704 based on the relationshipbetween updated meter BG value 520 and the most recent sensor Isig value524, and update the timestamp data 526 to reflect the updatedcalibration time. In accordance with one or more embodiments, the pumpcontrol system 720 stores or otherwise maintains previous meter BGvalues 520 and their corresponding sensor Isig values 524 (e.g., thesensor Isig value 524 contemporaneous to a respective meter BG value520) and calculates the updated sensor calibration factor 522 based onthe relationship between updated meter BG value 520 and the most recentsensor Isig value 524 along with the relationship between the previousmeter BG values and sensor Isig values. In one embodiment, the pumpcontrol system 720 determines the updated sensor calibration factor 522based on the updated meter BG value 520, the most recent sensor Isigvalue 524, the three previous meter BG values and their associatedsensor Isig values. After recalibrating the interstitial glucose sensingarrangement, the adaptive response process 1000 continues byreinitializing the closed-loop control mode using the new meter BGmeasurement value with the new sensor calibration factor for theinterstitial glucose sensing arrangement (task 1008). In this regard,the closed-loop initiation module 502 of the pump control system 720 mayutilize the updated sensor calibration factor 522 and the updatedcalibration time 526 along with the updated meter BG value 520 whendetermining whether the closed-loop mode can be initiated in conjunctionwith the control process 600 of FIG. 6.

In the illustrated embodiment of FIG. 10, when the adaptive responseprocess 1000 identifies an anomalous condition, the adaptive responseprocess 1000 continues by generating or otherwise providing a usernotification indicating the anomalous condition (task 1014). Forexample, the pump control system 720 may generate or otherwise provide avisual or graphical user notification on the infusion device 702, theglucose sensing arrangement 704, or via another remote devicecommunicatively coupled to the pump control system 720 (e.g., the CCD106, the computer 108, or the like) that notifies the user that theglucose sensing arrangement 704 should be repaired, replaced, orotherwise modified before the closed-loop control mode can bereinitiated. In exemplary embodiments, the pump control system 720generates the user notification in accordance with the user's alertconfiguration information in a similar manner as described above. Forexample, when the user normally uses the closed-loop control modeovernight while sleeping, the user may desire that a text message,e-mail message, or another remote notification be generated that theuser can receive the next day via the user's mobile device, personalcomputer, or the like (e.g., the CCD 106, the computer 108, or the like)to remind the user to remedy or otherwise address the anomalouscondition of the glucose sensing arrangement 704.

In exemplary embodiments, when the adaptive response process 1000identifies an anomalous condition, the adaptive response process 1000provides an alternative control of the user's glucose level in lieu ofreinitializing the closed-loop mode (task 1016). In this regard, thepump control system 720 may operate the motor 732 in accordance with thealternative control mode identified based on the type of alert conditionthat was previously detected by the pump control system 720. Forexample, as described above in the context of FIG. 5, if the alertcondition was detected by the model supervisor module 514 based on adeviation between the estimated glucose value and the sensor glucosevalue and the updated meter BG value 520 indicates an anomalouscondition of the interstitial glucose sensing arrangement 704, the pumpcontrol system 720 may operate the motor 732 in an open-loop mode toprovide an overnight basal delivery rate to the user (e.g., block 976).Conversely, if the updated meter BG value 520 does not indicate ananomalous condition of the interstitial glucose sensing arrangement 704,the pump control system 720 operates the motor 732 in the closed-loopmode (e.g., block 574) using the updated (or new) sensor calibrationfactor 522 (e.g., tasks 1008, 1012).

Still referring to FIG. 10, in exemplary embodiments, the adaptiveresponse process 1000 also identifies or otherwise determines whetherthe new meter blood glucose measurement value is indicative of apotential low blood glucose condition, and if so, generates or otherwiseprovides a user notification that indicates the potential low bloodglucose condition (e.g., tasks 1018, 1020). In this manner, the pumpcontrol system 720 automatically notifies the user of the potential lowblood glucose condition so that the user may take appropriate correctiveaction. For example, the pump control system 720 may generate orotherwise provide a visual and/or auditory notification that indicatesthat the user should consume carbohydrates to raise his or her bloodglucose level. Again, the low blood glucose user notification may begenerated in accordance with the user's alert configuration information,so that the user may control the manner in which he or she is notified.For example, some users may be content with only a visual low bloodglucose notification, while other users may desire an additionalauditory and/or a haptic notification of the potential low blood glucosecondition.

For the sake of brevity, conventional techniques related to glucosesensing and/or monitoring, sensor calibration and/or compensation, andother functional aspects of the subject matter may not be described indetail herein. In addition, certain terminology may also be used in theherein for the purpose of reference only, and thus is not intended to belimiting. For example, terms such as “first,” “second,” and other suchnumerical terms referring to structures do not imply a sequence or orderunless clearly indicated by the context. The foregoing description mayalso refer to elements or nodes or features being “connected” or“coupled” together. As used herein, unless expressly stated otherwise,“coupled” means that one element/node/feature is directly or indirectlyjoined to (or directly or indirectly communicates with) anotherelement/node/feature, and not necessarily mechanically.

While at least one exemplary embodiment has been presented in theforegoing detailed description, it should be appreciated that a vastnumber of variations exist. It should also be appreciated that theexemplary embodiment or embodiments described herein are not intended tolimit the scope, applicability, or configuration of the claimed subjectmatter in any way. For example, the subject matter described herein isnot limited to the infusion devices and related systems describedherein. Moreover, the foregoing detailed description will provide thoseskilled in the art with a convenient road map for implementing thedescribed embodiment or embodiments. It should be understood thatvarious changes can be made in the function and arrangement of elementswithout departing from the scope defined by the claims, which includesknown equivalents and foreseeable equivalents at the time of filing thispatent application. Accordingly, details of the exemplary embodiments orother limitations described above should not be read into the claimsabsent a clear intention to the contrary.

What is claimed is:
 1. A system comprising: one or more processors; andone or more processor-readable storage media storing instructions which,when executed by the one or more processors, cause performance of:switching operation of an infusion device from a first mode of fluiddelivery to a second mode of fluid delivery, the first mode beingdifferent from the second mode; receiving user input after the infusiondevice is operating in the second mode, the user input being indicativeof whether the infusion device should remain operating in the secondmode or transition from the second mode to a different mode; andoperating the infusion device in a manner that is influenced by the userinput.
 2. The system of claim 1, wherein switching operation of theinfusion device from the first mode to the second mode is performed inresponse to detecting an alert condition based on obtaining, from asensing arrangement, a sensor value for a physiological condition of auser.
 3. The system of claim 2, wherein operating the infusion device inthe manner that is influenced by the user input comprises: transitioningfrom the second mode to the first mode upon determining that the sensorvalue corresponds to an updated glucose reference value.
 4. The systemof claim 2, wherein operating the infusion device in the manner that isinfluenced by the user input comprises: transitioning from the secondmode to a third mode upon identifying an anomalous condition based onthe sensor value and an updated glucose reference value.
 5. The systemof claim 1, wherein the user input is a response to a user notificationprovided in accordance with user-specific alert configurationinformation.
 6. The system of claim 1, wherein the first modecorresponds to a closed-loop mode.
 7. The system of claim 1, wherein thesecond mode corresponds to a mode in which a pre-programmed basal rateis delivered.
 8. A processor-implemented method comprising: switchingoperation of an infusion device from a first mode of fluid delivery to asecond mode of fluid delivery, the first mode being different from thesecond mode; receiving user input after the infusion device is operatingin the second mode, the user input being indicative of whether theinfusion device should remain operating in the second mode or transitionfrom the second mode to a different mode; and operating the infusiondevice in a manner that is influenced by the user input.
 9. The methodof claim 8, wherein switching operation of the infusion device from thefirst mode to the second mode is performed in response to detecting analert condition based on obtaining, from a sensing arrangement, a sensorvalue for a physiological condition of a user.
 10. The method of claim9, wherein operating the infusion device in the manner that isinfluenced by the user input comprises: transitioning from the secondmode to the first mode upon determining that the sensor valuecorresponds to an updated glucose reference value.
 11. The method ofclaim 9, wherein operating the infusion device in the manner that isinfluenced by the user input comprises: transitioning from the secondmode to a third mode upon identifying an anomalous condition based onthe sensor value and an updated glucose reference value.
 12. The methodof claim 8, wherein the user input is a response to a user notificationprovided in accordance with user-specific alert configurationinformation.
 13. The method of claim 8, wherein the first modecorresponds to a closed-loop mode.
 14. The method of claim 8, whereinthe second mode corresponds to a mode in which a pre-programmed basalrate is delivered.
 15. One or more non-transitory processor-readablestorage media storing instructions which, when executed by one or moreprocessors, cause performance of: switching operation of an infusiondevice from a first mode of fluid delivery to a second mode of fluiddelivery, the first mode being different from the second mode; receivinguser input after the infusion device is operating in the second mode,the user input being indicative of whether the infusion device shouldremain operating in the second mode or transition from the second modeto a different mode; and operating the infusion device in a manner thatis influenced by the user input.
 16. The one or more non-transitoryprocessor-readable storage media of claim 15, wherein switchingoperation of the infusion device from the first mode to the second modeis performed in response to detecting an alert condition based onobtaining, from a sensing arrangement, a sensor value for aphysiological condition of a user.
 17. The one or more non-transitoryprocessor-readable storage media of claim 16, wherein operating theinfusion device in the manner that is influenced by the user inputcomprises: transitioning from the second mode to the first mode upondetermining that the sensor value corresponds to an updated glucosereference value.
 18. The one or more non-transitory processor-readablestorage media of claim 16, wherein operating the infusion device in themanner that is influenced by the user input comprises: transitioningfrom the second mode to a third mode upon identifying an anomalouscondition based on the sensor value and an updated glucose referencevalue.
 19. The one or more non-transitory processor-readable storagemedia of claim 15, wherein the user input is a response to a usernotification provided in accordance with user-specific alertconfiguration information.
 20. The one or more non-transitoryprocessor-readable storage media of claim 15, wherein the first modecorresponds to a closed-loop mode.